Why do complex sentences differ from compound sentences?

Why? I don't know!

How do they differ? That's pretty easy!

Compound sentences are two simple sentences (or two independent clauses) joined with a coordinating conjunction + comma or with a semicolon. (Each part of a compound sentence can be a sentence on its own.)

Complex sentences are made up of one independent (main) clause and at least one dependent (subordinate) clause. These clauses can be joined by means of subordinating conjunctions, relative pronouns, or interrogative pronouns. (Only the main clause can be a sentence on its own; the subordinate clause/clauses cannot stand on its/their own).

http://grammar.ccc.commnet.edu/grammar/sentences.htm#sentence_types

Thanks😂

You're welcome!