Here are some examples:
* Post-war: After the war
* Post-graduate: After graduation
* Post-mortem: After death
* Post-traumatic stress disorder: A condition that develops after a traumatic event
* Postscript: A note added after the main body of a letter
It can also indicate "behind" or "in the back", as in:
* Posterior: Located at the back of something
Sometimes, "post-" can also mean "related to" or "connected with", especially when referring to specific fields or topics:
* Postmodern: Related to the postmodern period
* Post-impressionism: A style of painting that followed Impressionism
* Post-structuralism: A school of thought that emerged after structuralism
Overall, the meaning of "post-" is quite flexible and depends on the context in which it's used.