A core and a thread are two related but different concepts in computer architecture.

A core is a physical unit of a processor that performs computation. Each core can execute instructions independently, allowing for parallel processing of multiple tasks. A core is considered a basic building block of a CPU and is capable of executing a single task at any given moment.

A thread, on the other hand, is a software concept that represents a separate execution path within a process. Each thread runs independently, but it shares the same memory and resources as the process it belongs to. In a multi-threaded process, multiple threads can run concurrently, allowing for efficient use of the available CPU cores.

So, to summarize, a core is a physical unit of a processor that performs computation, while a thread is a software-level concept that represents a separate execution path within a process. A single core can run multiple threads, allowing for parallel processing of multiple tasks.