Punctuation marks help the reader understand what the writer is trying to say
A semi-colon looks like this ;
Semi-colons are used to separate items in complicated lists - 'We can play with small, bouncy balls; shiny, red bikes; and new, plastic hoops at playtime.'
Semi-colons are also used to connect two closely-related independent clauses - 'An old woman lived in a small cottage; it was near a ruined castle.'