Complex sentence: The best-known component on top of Netfilter is the firewall which filters packets, but the hooks are also used by other components which perform network address translation, stateful tracking and packet enqueueing to user space.
Split into simpler sentences: The best-known component on top of Netfilter is the firewall which filters packets. However, the hooks are also used by other components which perform network address translation, stateful tracking and packet enqueueing to user space.