Stopcocks are an essential component of water and gas pipelines, controlling the flow of fluids. However, there are different synonyms for this particular word. Valve is one of the synonyms for stopcocks that holds the same function. Tap and faucet, on the other hand, are synonyms mainly used in plumbing for controlling water supply. Meanwhile, cockscrews are mechanical stopcocks that work more in heavy-duty machinery. On the flip side, shut-off valves are often used to stop the flow of water and gas automatically in an emergency situation. Lastly, isolation valves are installed to isolate a particular area in the pipeline system, allowing for maintenance work to be carried out safely.