What is a thin client (lean client)?
A thin client (lean client) is a virtual desktop computing model that runs on the resources stored on a central server instead of a computer's resources. Thin clients typically take the form of low-cost computing devices that heavily rely on a server for computation. The term also describes software applications that use the client-server model in which the server performs all processing.
Businesses, IT personnel and public environments, such as libraries or government offices, use thin clients because of their security, scalability and manageability.
Thin clients connect to a server-based computing environment. The server stores data like applications and memory. Essentially, a server holds the desktop environment. Thin client management is server-side, with a virtual desktop infrastructure (VDI). Thin clients and other lean devices rely on a constant network connection to a central server for full computing and don't process much on the hardware itself.
The term thin client derives from the fact that small computers in networks tend to be clients and not servers. Networks use thin clients to limit their capabilities to only essential applications. Users purchase them, and they remain "thin" regarding the client applications included. Examples of thin clients include PCs and mobile devices.
Thin client use cases
Businesses across industries give employees thin clients for many reasons. Thin clients can replace computers and help access virtual desktops or virtualized applications. It's generally more cost-effective to use thin clients rather than a computer that processes data locally. This is because each thin client doesn't need to be as new or powerful since servers do most of the processing.
Thin clients are also usable in remote environments, so users don't have to worry about fixing their PCs as much. If the endpoint device downloads most of its data from a server, the client side has fewer moving parts. Organizations that need more secure endpoint devices might choose thin clients over other architectures.
Still, thin clients aren't the best choice in every situation. Users must be in an environment with a strong and stable network connection. Intensive applications might run slow, as multiple people might access the network simultaneously. Thin clients are best for organizations with less intensive applications and that have the back-end infrastructure to support each thin client's needs.
Workplace examples of thin clients
An example of a thin client is a set of endpoint devices in a government office where many people use the same machine. Thin clients are more secure because they enable users to access office data and applications through a server rather than locally.
Because the server handles processing and computationally heavy tasks, the endpoint device can be a bit older with less expensive hardware. Older computers can push to run applications on the server for quick performance. Windows Remote Desktop Device is a proprietary protocol for remote desktops and applications.
Libraries also use thin clients connected to a central server. This facilitates the use of multiple easily manageable devices at once.
Thin client architecture
A data center server that uses cloud computing-based architecture can take on multiple clients' processing load. Thin clients keep hardware and software lightweight, as the devices only use clients for essential applications. This reduces the need for client-side setup or administration. The server also centralizes user assets and data recovery tasks for better visibility and scalability.
With a lightweight client side, the central server takes on much of the processing load and holds most of the data. The data center server centralizes critical IT assets to better use and allocate resources. Some resources the central server handles include memory and use of processor cores. Therefore, securing the central server is crucial.
How do thin clients work?
Businesses can use thin clients in three different ways. Even though these approaches are different, they have the same goal of keeping client hardware and software as lightweight as possible. The ways to use thin clients are the following:
- Shared terminal service. In a shared terminal service, all clients share a server-based OS and applications.
- Desktop virtualization. With desktop virtualization, each desktop is a virtual machine partitioned from a central server. Although the OS and applications aren't shared resources in this instance, they remain stored in the central server.
- Browser-based approach. This approach is different from a typical thin client system because functions execute from within a web browser instead of on a central server, and the thin client processes data. This form retrieves software and data held on a network.
Thin client hardware generally has low-energy processers, has low levels of RAM and hard disk drive space, and offers lower performance levels compared to a typical computer. It requires minimum processing power to boot up the device and connect to the server. Thin clients are designed to connect to a more powerful central server. Even though the client isn't as powerful, users still interact with it as if it were a typical computing device.
Be sure to minimize thin client software. On the client side, software should be an OS that enables the device to connect the central server. Once the thin client turns on, the device should receive the Internet Protocol address and connect to a server with a protocol or another software. The user can then log in to the server and access its resources.
The central server must be advanced enough to handle multiple client sessions at once and prevent outages and bottlenecks. The server should connect to each client consistently to ensure each one can continue to work.
Benefits and drawbacks of thin clients
Benefits of thin clients include the following:
- Less vulnerable to malware attacks.
- Longer lifecycles.
- Less power consumption.
- Inexpensive compared to regular PCs.
- Better, centralized manageability.
- Improved scalability.
However, thin clients also have some downsides. Drawbacks of thin clients include the following:
- Requires a continuous network connection.
- Works slower than internal computer components.
- Suffers from bandwidth and performance bottlenecks.
- Require large servers to deliver the appropriate number of resources to each client.
Thick clients vs. thin clients vs. zero clients
Thick clients are desktop PCs that can handle all the functionality of a server if required. Thick clients have most resources installed locally rather than distributed over a network. Thick client devices use their own hard drives, software applications and other local resources. These devices contain most, if not all, essential components.
A thin client, however, is a low-cost network computer that relies heavily on a server for its computational role. Thin clients limit computing capabilities to only essential applications. Compared to thick clients, thin clients are easier to manage and protect networks from security risks. They also lower the costs of maintenance and licensing.
The biggest difference between thick clients and thin clients is thin clients rely on a network connection for computing and don't process much on the hardware. Thick clients don't need constant network connection and do much of the processing for client-server applications.
An ultrathin client is known as a zero client. A typical zero client product is a small box that connects a keyboard, mouse, monitor and Ethernet connection to a remote server. Users can access the server, which hosts the client's OS and software applications, wirelessly or with cables. VDI environments often use zero clients.
History of thin clients
Thin clients might seem like a modern invention, but they have been around for quite some time -- before the term was even coined. Thin clients come from multiuser systems that access a mainframe from a computer terminal. These pivoted from providing command-line interfaces to graphical user interfaces. In 1984, Unix supported devices that ran display server software, also known as graphical X terminals.
In 1993, Tim Negris, vice president of server marketing at Oracle, coined the term thin client. Negris hoped to differentiate Oracle's server-oriented software from Microsoft's desktop-oriented products. In 1995, Windows NT began supporting a multiuser OS with Windows NT 3.51.
In the 2010s, thin clients broadened from only PCs to mobile devices, such as Windows- or Linux-based tablets.
