Eli5, what does ‘enriched’ mean in the context of, for example, ‘enriched uranium’?

Question

Eli5, what does ‘enriched’ mean in the context of, for example, ‘enriched uranium’?

In: Physics

Answer 1

This is when the percentage of U^235 has been increased through separation of the isotopes.

There are a number of ways this can be done and it’s often very costly and time consuming.

https://en.wikipedia.org/wiki/Enriched_uranium