What is I/O bound and CPU bound?

An I/O bound task spends most of its time waiting for input/output operations to complete (network, disk, database). A CPU bound task spends most of its time performing computations on the processor.

Examples:

• I/O bound: Reading a large file from disk, sending a request to an external API, working with a database.
• CPU bound: Cryptographic calculations, image processing, complex mathematical computations.

For I/O bound tasks, asynchronous programming (async/await) is often used to free up the thread during waiting. For CPU bound tasks, it is more effective to use multithreading (Task.Run, Parallel.ForEach) to parallelize computations across processor cores.