Which software is usually divided into two categories, client and server?

The software that is commonly divided into two categories, client and server, is network software. This classification is essential for understanding how different components of a network interact with each other.

In a client-server architecture, the client refers to the software that runs on a user's machine, requesting services from the server. The server, on the other hand, provides resources or services to multiple clients. This division is foundational in networking, as it helps to streamline processes such as data requests, resource sharing, and communication between different devices within a network.

Understanding this distinction helps in grasping how network applications operate, such as web browsers (clients) accessing web servers, database clients querying database servers, and email clients retrieving messages from mail servers. This architecture is central to many modern distributed systems and is key in designing and troubleshooting networked solutions.