what does this semi colon mean or in short this sign ->[ ; ]<- ?

can someone help me about this semi colon because when ever i watch some scripting tutorial they're sometimes adding semi colon and they're not explaining what does that semi colon mean but i try to find in wiki but i can't find any info about semi colon so if anyone can help me i really appriciate it and thanks for reading my question

Many programming languages like Javascript and PHP require that you put a semicolon after each statement. In Roblox Lua, semicolons are totally optional, and so some people use them out of habit, and others don't.