Script abuse, or scripting abuse is when a player abuses scripts to be an annoyance or nuisance to other players. Unlike admin abuse, script abuse can do many unnecessary and inappropriate things. The most common is "kicking" a player from the game. Sometimes these players will run scripts that spam the workspace, or compromise the game in an extreme way.
They always go on the game Script Builder. That game, and many other games like that "allow" players to script, therefore, players can script abuse.
It is very hard and/or nearly impossible for a player to load scripts on other games. The only way they can is if they hack or exploit or get another one's account.