Sorry, I should have specified: This is in the United States. Here "inventions" is specifically patentable stuff. See https://www.uspto.gov/patents-getting-started/general-inform...
Inventions is usually defined in the contract itself and does not necessarily apply to patentable things.
This is just my personal experience, so take it for what it's worth, though I do have a fair amount of experience with contracts and non-competes.