Server and Clients overview
Service providers at a glance
A server dictionary provides clarity
The inflationary use of the term server often causes confusion. Here is an attempt at a compilation of the most common server types, types and applications.
Servers offer special services to their customers (clients) – similar to what a waiter in a restaurant does. By server we mean a very powerful computer (hardware) or a program (software) that runs on a fast machine alongside other server services. Usually these computers are built into a rackmount housing. The latter, in turn, is installed in a server cabinet within a data center. Of course, the term “server” also applies to a combination of hardware and software.
1U server, 2U server
A division of server housings based on the space required. As a result, servers in a 19-inch rackmount enclosure in the data center usually occupy between one and four height units (1U corresponds to 44 millimeters).
A
Access Server, Network Access Server
An access server is operated by an Internet Service Provider. It thus enables its customers or, in the case of a company network, an intranet to access the Internet or, in the case of a company network, an intranet.
Application server, application server
Application server is an umbrella term for computers in a network. This means that they use special software to provide tasks in the network such as directory services, tracking or route planning.
Authentication server
Authentication servers nevertheless monitor the connections in a computer network. Among other things, it stores user IDs, passwords and IP addresses of the logged in clients in a database. For example, Windows Domain Controller, Remote Authentication Dial-In User Service (RADIUS), or Extended Single Sign-On (XSSO) belong in this category.
B
Bare Metal Server, Single Tenant Server
This is a physically existing server (as distinct from a virtual server or hypervisor server) in the data center. The customer has the exclusive right of use and also full access to this dedicated managed server.
blade server, server blade, brick server
Blades/Bricks are quasi single-board computers or components in modular design, whereby several of them can be accommodated in one housing. Individual blade servers therefore usually have neither their own power supplies nor cooling. Usually only the main memory is used as memory. However, own drives are often also not available.
C
Chat server
These servers thus ensure the synchronous transmission of chat messages between the registered participants. Protocols such as Internet Relay Chat (IRC) or Extensible Messaging and Presence Protocol (XMPP) are used for this.
Client-Server, Client-Server model
Actually, the term only describes a system architecture. Tasks and services are distributed within a network according to this principle. The client can use or request the service of a server. The server from the same network, however, offers its services to several clients simultaneously.
Cloud server
Cloud servers are virtual servers that are accessible via an open network such as the Internet. The major cloud providers include Amazons (AWS), Google (Google Cloud Platform), Microsoft (Azure) and IBM (IBM Cloud).
D
Database server
To effectively manage and store large amounts of data, data is stored in databases. Database servers are specialized in making the data of many clients accessible at any time and simultaneously. Common applications include DB2 and Informix, Microsoft SQL and Oracle.
Dedicated Server
Counterpart to a virtual/shared server: A dedicated server is physically present in the data center and therefore usually has a fixed IP address. He has unlimited user rights and thus offers complete access to his resources. As a result, customers can charge such servers with particularly high-performance applications. However, they are also responsible for maintenance and thus for update management.
DHCP server
The DHCP (Dynamic Host Configuration Protocol) ensures the automatic assignment of a network configuration of the clients available in the network for this purpose. If the volume is high enough, this can be done by a separate server. In the home network, this task is usually performed by the router.
Digital Media Server, DMS
Digital Media Servers provide media content in the internal network that can be accessed via DLNA/UPnP. Digital Media Player (Smartphone, PCs) and Digital Media Renderer (TV) can therefore easily access the movies, pictures, music of the server. Digital media servers usually run on media streamers in the network such as set-top boxes, recorders or media PCs.
DNS Server, Domain Name Server, Name Server
Domain name servers (DNS) are used for simple network communication: They convert web addresses into IP numbers. As a distributed database, they process DNS requests that were entered, for example, via a browser. They translate the names into machine-readable addresses of the desired network resource.
domain controller
Domain controllers are servers within a network, which manage and control the corresponding domain with the included clients.
Printer server & Clients
Printer servers are accessible as a service in the network and manage the print jobs of all clients present there. As a result, they act as an intermediary between your own PC and a network printer.
E
E-mail server
E-mail servers manage mailboxes, store messages and ensure that they are received and sent.
ESX Server, ESXi Server
However, as a virtualization solution, an ESX Server with VMware comes with its own operating system. It thus provides virtual Windows and Linux systems. Thus it is possible to run and manage several virtual machines on one server. The administrator also has the opportunity to use his hardware to its optimum capacity and to react more flexibly to bottlenecks.
Exchange server
Microsoft Exchange Server is used as server software for optimized internal communication. It thus enables central management of e-mails, appointments, tasks and contacts for all users via the Microsoft Outlook client software.
F
File server, file server, download server
File servers are machines that release compiled data for users in the network. They can sometimes be restricted to a closed user group or even be freely accessible to all. The latter therefore rather describes a download server. However, the CD-ROM server is an obsolete subtype of this.
FTP server
The administrator transfers to a file server the data that he wants to make available to one or more users. For this purpose, they are usually transferred via File Transfer Protocol (FTP) (in upload and download). This type of fast data transmission was therefore also the inspiration for its name.
G
Game server
Onlinebased multiplayer games sometimes require a central server or administrative software that enables synchronous play by the logged-in participants. Such platforms can also be rented in the data center and set up in the internal network.
GPU Server
GPU servers are extremely fast computers, which have been optimized for floating point calculations. They achieve this by having fast graphics processors (in addition to the obligatory main processors) do the pure computing work. This enables you to achieve performance in the three-digit TerraFLOP range (Floating Point Operations Per Second) and thus work in this discipline much faster than conventional servers.
groupware server
Groupware servers offer not only groups but also people a shared working environment. This allows them to work together on one or more projects in their area of responsibility via a common interface.
H
Home server
Collective term for a central PC, which consequently provides all kinds of services in the home network. These can be functions such as media streaming, file transfer or home automation. (Often simultaneously.)
K
Combination server
Combination servers basically consist of several servers or blades and the associated storage.
Communication server
Generic term for hardware and software models that allow communication between LAN PCs and computers outside the local network. However, they have the ability to translate LAN-specific protocols into external ones. This group includes file servers, mail servers, fax servers and others.
L
Linux server, Debian server, Ubuntu server
Among the server operating systems, Linux has now established itself as a free Unix variant. There are numerous distributions, including for example CentOS, Debian, Red Hat Enterprise and Ubuntu. Consequently, users receive the same professional support for open source operating systems as commercial platforms.
List server
List servers do not usually consist of hardware, but are usually designed as a service in the network. Users can thus register via mail or web to receive news via the resulting distribution list.
M
Managed server
Managed in this context means support by the operator: the server is then managed by the web host himself. As a service, it provides the necessary maintenance and, for example, also imports important updates.
Mapserver
Web services for geoservices are calculated via a map server and provided to the customer for this purpose. It manages the geodata and returns the map material.
Microserver
The term Microserver is only vaguely defined. Many suppliers sell particularly small case variants under the label. Starline now refers to the independent units that make up a Ceph storage appliance (Mars 400) from Ambedded as microservers. Finally, each of these eight microservers has its own CPU, its own main memory and separate data carriers.
Microsoft Windows Server
With its professional operating system line, Microsoft uses names such as “Windows Server 2019”. It contains numerous applications and options for virtualization.
N
NAS server
A NAS server or short NAS (Network Attached Storage) usually has two or more storage devices and also has fast network access built in. In addition, a sophisticated access control system and detailed user administration ensure increased data security. Equipped in this way, they provide access to all authorized clients inside and, if required, also outside the local network. The use cases are sometimes diverse: they can be used as private cloud, media archive, backup target or for productive data.
NetWare server
Servers that worked with the previously widely used NetWare operating system from Novell. It was used there to provide file systems, printers and directory services.
News server
News servers exchange text messages in Usenet via the NNTP protocol.
P
Proxy server
Proxy servers work as intermediaries between the servers and clients. They are used to separate the direct data stream between server and client. The proxy server then receives a request from the client and forwards it as if the client would make one himself. The server response follows the same pattern. For this reason, it guarantees, among other things, anonymity of the requests.
R
Rack server, rackmount server, server rack (server cabinet)
In order to optimize the space available for IT solutions in companies or data centers, many of the necessary components are installed in 19-inch rackmount housings (48 centimeters wide) – these can be servers, storage, switches or UPSs, for example. Enclosures in this format also have a defined height in a grid of 4.4 centimeters, which was defined as one unit (1U). This way, the standardised 1, 2, 3 or 4U server housings can be screwed into the server racks, some of which are as high as the ceiling, to save space.
S
Samba Server
Samba servers are used for data exchange between Windows and Linux computers. The name Samba comes from the SMB protocol (Server Message Block), which in the meantime has been extended by the Common Internet File System (CIFS) to provide services such as Windows RPC in addition to file and printer sharing.
Server cluster
A server cluster represents a computer network of several servers, which therefore offer a much higher reliability and also deliver a higher performance. The accessing clients usually still perceive a cluster as a single server.
Server farm
Group of many similar servers, which are thus interconnected to form a logical system. The resulting redundancy ensures high performance and high availability: if one server fails, another one takes over.
Shared Server, Non-Dedicated Server
Shared servers are not exclusively dedicated to a single client or task – unlike a more expensive dedicated server. In addition to the lower costs, a shared server has the advantage that the operator can counteract and, if necessary, compensate for load peaks by load balancing.
Short Depth Server, Pizza Box
Short Depth Servers with their shallow depth fit into the particularly slim telco racks of a data center. Colloquially they are therefore also called pizza boxes.
Storage Server
Storage servers provide storage space over the network. They can be designed as NAS or integrated into a Storage Area Network (SAN). The storage space is provided by HDDs or SSDs. Depending on its structure, access to it can be block-based or file-based.
Streaming server, audio/video server
Streaming servers send audio or audio/video data streams to their clients. This could be Internet radio or WebTV, for example. Depending on the platform, proprietary programs, browsers or AV software, such as the free VLC media player, are sometimes used to output or display the streams.
Surveillance server
Server, for simultaneous processing of various video cameras and microphones. The cameras networked for monitoring purposes deliver their data streams directly or indirectly to the server, which stores and manages them redundantly. You can set the point in time from which older recordings can be overwritten or which situations trigger the storage of data streams.
SVN server, Apache Subversion server
Apache Subversion or SVN as free software offers a central version management of files and directories. Central project archives (repositories) can be managed in this way. Changes to content can then be transferred from the workstations to the repository.
T
telnet server
Telnet servers accept text-based input and output (via Telnet protocol) for remote control.
Terminal server, VNC server
Terminal server stands for server software and hardware where the necessary programs are executed on a mainframe computer. The server and client/terminal only exchange the screen content and mouse or keyboard entries. Today, Virtual Network Computing (VNC) or the Remote Desktop Protocol (RDP) is used for this purpose.
Time server
Time servers return the current time to the requesting system via the Network Time Protocol (NTP). So they are used for time synchronization of NAS, workstations and other servers.
U
Monitoring and management server
General term for servers that monitor or manage systems and clients. Depending on the type and configuration, they work only in a monitoring mode or act in both directions.
V
Directory Service Server
Directory services servers collect and manage the data of users, computers and the necessary access rights in the local network.
Video server
Server optimized for the processing, distribution and storage of video data streams. In particular, he has the ability to work with the protocols commonly used in the video sector.
Virtual server, hypervisor server
Virtual servers access a process called a hypervisor. For this purpose, the hypervisor manages the allocation of resources (CPU, memory, interfaces, etc.) as if there were only one operating system. The modern, high-performance hardware thus allows up to thousands of virtual servers to be run in parallel on one physically existing server.
VPN server
A server that supplies a client via VPN (Virtual Private Network, VPN) service. After checking the access data, the server sends the client the requested information via a secure connection.
W
Web Server, Web Application Server, Apache HTTP Server
If you call up an address in your browser, the page – or the texts and images – are sent from a web server set up for this purpose. They are often named after the server software they use, such as the widely used Apache Software Foundation.
X
XEN Server
XEN is a hypervisor that allows multiple virtual servers to run on a dedicated physical machine.
Z
Zealbox server
Zealbox is an established private label from Starline. Meanwhile, servers from various application areas are operating under this label. These can be infrastructure, GPU and storage servers. For this purpose, they are individually handcrafted from high-end components in Kirchheim unter Teck, depending on requirements.
