[usaar333]

That depends on the plan. Plenty of private companies don't release the shares as they vest. Larger ones - and public ones - generally will though.

[srtjstjsj]

Then what does "vest" mean? Are you conflating options with RSUs?

[sokoloff]

Vest but not release simply means that you've earned the right to those shares (vested), but that you don't actually have ownership of the shares (released) until some later time or event triggers the release.