Pipes come in all sorts of sizes but eventually they need to connect. And sometimes they need to connect with each other. While the connections are sometimes straight, at other times they may take a turn in direction. For those situations, pipe fittings help to connect pipes of different sizes and diameters and help pipe lines to change direction, often abruptly. And in the case of underground sprinklers, an opening needs to be in place for the sprinkler head.
Pipe fittings, like pipes themselves, come in different types of material. They can be made of stainless steel, copper, or PVC (which is short for polyvinyl chloride) to name a few. While many are rounded, there are other types of fittings. Male and female, plain end bell or socket, pipe clamp ends, or ribs are just a few. They are as varied as the pipes they connect and have varied requirements for strength depending upon the pipes and the material that they are expected to funnel, whether it is solid or liquid.