Business Rules are server-side so they only run on the server-side.
They will never execute on the client-side and we have our server-side on the top right.
So any time you see this it's safe to assume that that particular component is server-side.
So the service now docs state a business rule is a server-side script that runs when a record is displayed inserted updated or deleted or when a table is queried for the rest of this section we'll discuss what exactly this means.
So business rules are probably the most common scripting location within service now and business rules are actually javascript that runs on the server.
