Semicolons (;) separate independent clauses that are related in meaning, and they separate items in a list when those items themselves are long or include commas. For example, this summary could say "Semicolons are useful; they show that clauses are related in meaning."
Learn when to use a semicolon to connect two related independent clauses in one sentence or to separate items in a complex list.
You can use a colon to draw attention to many things in your writing. The categories listed below often overlap, so don’t worry too much about whether your intended use of the colon fits one category perfectly.