Client Access License (CAL)

Definition:

A Client Access License (CAL) is a type of software license that grants a user or device the right to access and use specific services or resources on a server. CALs are commonly used in the context of server software, such as Microsoft Windows Server, to regulate and manage client connections to the server.

Let's illustrate this with an example:

Imagine you are running a small business with a local network of computers, and you decide to set up a Windows Server to centralize resources like file storage, printer sharing, and user authentication. To access the services and resources on the Windows Server, each user or device connecting to it will require a CAL.

Example Scenario:

User CAL:

Let's say you have 10 employees in your company, and each of them uses their own computer to access files and printers on the server. In this case, you would need to acquire 10 User CALs. These User CALs will be associated with each individual user and allow them to connect to the server from any device they use (such as their work computer, laptop, or even a personal device).

Device CAL:

Alternatively, you might have a scenario where you have 10 computers shared among 20 employees who work in shifts. In this case, if you choose to go with Device CALs, you would need to acquire 10 Device CALs. Each Device CAL allows a specific device (e.g., a computer) to connect to the server. So, no matter which employee is using the device, as long as it's one of the 10 computers with Device CALs, they will be able to access the server's resources.

It's essential to understand that the choice between User CALs and Device CALs depends on your organization's specific needs and the number of users or devices that will be accessing the server.

Keep in mind that CALs are not limited to Windows Server; other server software and applications might also require CALs or similar licensing mechanisms to control access.

Licensing models and regulations can be complex, and it's always a good idea to consult with the software vendor or a licensing expert to ensure compliance with the terms and conditions of the licenses you purchase.