What is the difference between irony and satire, and parody and sarcasm?
They're similar, but do have some differences.
Satire is the use of humor, irony, exaggeration, or ridicule to expose and criticize people's stupidity or vices, particularly in the context of contemporary politics and other topical issues. Irony is often a tool used in satire, and is when you convey a meaning by using language that normally signifies the opposite, typically for humorous or emphatic effect.
Parody is a type of satire that doesn't really make a point; it's just satire for the purpose of being funny. Sarcasm is the use of irony to mock or convey contempt. So sarcasm is a type of irony.
So let's see if I can clarify everything. Satire is the overarching one here. Parody and irony are subsets of satire, and sarcasm is a subset of irony.