system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The difference between agonists, partial agonists, inverse agonists and antagonists

The last two are really confusing me. All help is much appreciated!

&#x200B;

Cheers!

Edit: Thanks so much for the overwhelming response guys. I really appreciate it!
gpt
Agonist = molecule that binds to receptor and acts like the endogenous ligand, causing X effect.

Partial agonist = molecule that binds to receptor and acts like the endogenous ligand but partially causes X effect. Not as strong. When placed with an agonist, acts as a competitive antagonist. 

Inverse agonist = molecule that binds ot receptor and causes the opposite effect of X.

Antagonist = molecule that binds to receptor and does nothing. Does nothing if agonist is not present, but has a 'negative' effect if the agonist is present. Can be competitive, taking the same spot as the agonist, blocking it, or noncompetitive, taking another spot that completely stops the receptor from working.