What are Cores and Threads?

When we hear that “a computer has dozens of cores,” it sounds like immense power - but what does it actually mean?

Core

A core is the basic processing unit in a CPU. Each core can run an independent computation - meaning it can process one task at a time.

Modern computers have multiple cores, allowing them to run several tasks in parallel - for example:

• One core calculates the inference of a model,
• While another core handles data input,
• And another aggregates results.

This creates parallelism - multiple computations happening simultaneously.

What is a Thread?

A thread is a “sub-process” - an even smaller unit than a core. Each core can typically run several threads simultaneously (thanks to a technology called Hyper-Threading).

However, this doesn’t mean the reality is perfect. If two threads share the same core, they compete for the same resources, so you don’t always get double the performance.

Bottom Line

• Core = Physical computing power.
• Thread = A logical work unit managed on the same core.

The smarter tasks are allocated between cores and threads, the more efficiently the CPU is utilized.