A gate valve is a type of valve that has a gate-like disc that moves up/down to control the flow of a fluid. It's commonly used to regulate the flow of water, oil, and other fluids. A gate valve can either be fully open or fully closed, meaning that it can't regulate the flow of the fluid in the same way that a throttling valve can.
An isolation valve, on the other hand, is any type of valve that's used to shut off or isolate a section of a piping system. An isolation valve may be a gate valve, a ball valve, or even a butterfly valve. The purpose of an isolation valve is to allow maintenance or repair of a section of piping while keeping the rest of the piping system operational.
To summarize, a gate valve is a specific type of valve that regulates fluid flow, while an isolation valve is a general term that refers to any valve used to shut off or isolate a section of a piping system.
