Most software (including Python and Numpy and Go and pretty much every Rust program) runs on your computer's CPU. The CPU is good at running programs with a lot

Most software (including Python and Numpy and Go and pretty much every Rust program) runs on your computer's CPU. The CPU is good at running programs with a lot of different instructions and if-statements and loops and stuff. But for neural networks, people often prefer to use special hardware like graphics cards, since graphics cards are really good at doing relatively simple math on many pieces of data at once. So they create special libraries like TensorFlow that can send commands to the graphics card instead of doing the math on the CPU. (And they don't use Numpy because even though it's highly optimized, it's highly optimized for CPUs, and graphics cards are a lot faster than CPUs at running neural networks.)