Thick client

A thick client is a computer that performs the main processing of data and applications locally, without constant dependence on a server. In terminal and banking networks, such workstations independently run applications and only exchange data with a server.

What is a thick client

A thick client (fat client) is a full-fledged workstation where applications and data are processed on the device itself. Unlike a thin client, which only displays the image coming from the server, a thick client has its own processor, RAM and storage. The application is installed and runs locally, and the server is used for data storage and information exchange. A classic example is a personal computer with an installed office program that works even without a network.

How a thick client works

The workflow looks like this: the user launches an application on their computer, the data is processed by the processor and memory locally, and the result is saved to the local disk or sent to the server. If the server is unavailable, the thick client continues to work with the data already on the device and synchronizes changes after the connection is restored. This approach reduces the load on the server and the network, since only data is transmitted over the channel, not a graphics stream. To support the operation of several applications simultaneously, a thick client needs sufficient performance: a modern processor, from 8 GB of RAM and a fast storage drive.

Thick and thin client: differences

A thin client is a device that performs all computations on the server and only displays the image on its screen. It is cheaper, simpler to maintain and more secure, since data is not stored at workstations, but requires a stable connection to the server. A thick client, on the contrary, is autonomous, supports the operation of applications without a network and is better suited for programs with heavy graphics or local databases. The choice between them depends on the tasks: for centralized management and high security, thin clients are chosen, for autonomous operation and high performance — thick ones.

Use of thick clients in banks

In banking and corporate systems, thick clients are used where applications work with local data, specialized equipment or require high performance. For example, teller workstations, software complexes with cryptography and programs working with peripheral devices: printers, scanners and document readers. Thick clients continue to work when the network fails, which is critical for the continuity of operations. At the same time, it is important to ensure centralized updating of applications and protection of local data so that the device does not become a point of information leakage.

Advantages and disadvantages of thick clients

The advantages are autonomy in network failures, high application performance and the ability to work with local devices. The disadvantages are the higher cost of equipment, the complexity of centralized management and updating, as well as the risk of data leakage if sensitive information is stored on the device. In large organizations, the architecture is often built hybrid: basic tasks are performed by thick clients, and some applications are provided through terminal servers for flexible access.