Define the term 'cylinder head'.

The term 'cylinder head' refers to the component that closes the top of the cylinder in a reciprocating engine. It serves multiple critical functions, including sealing the combustion chamber, providing mounting points for valves and spark plugs, and facilitating the flow of air and fuel into the combustion chamber, as well as the exhaust gases out of it.

In addition to closing the cylinder, the cylinder head is designed to withstand the high temperatures and pressures generated during the combustion process. This component plays a vital role in the engine's efficiency and performance by ensuring that the combustion process occurs effectively and is contained within the cylinder.

Understanding the purpose of the cylinder head is essential for comprehending engine design and function, as it is integral to achieving optimal combustion and performance in reciprocating engines.