What does CAT mean in the context of Ethernet cables?

In order to describe the performance capability of a single component, the individual components of a network (cables and connectors) are categorised. In a network link, the component with the lowest performance capability (category) determines the transmission class of the entire system. Higher categories automatically cover the lower categories as well. The range is usually between cat5 and cat8 and is roughly described by the frequency and the amount of data that is transported.