This document discusses VLAN Trunking Protocol (VTP) which allows switches to exchange VLAN configuration information and manage VLANs across multiple switches. It describes VTP domains, modes, advertisements and pruning. VTP is configured on switches to synchronize VLAN information and eliminate incorrect configurations. Troubleshooting tools like "show vtp status" and "show interfaces trunk" are used to verify proper VTP configuration and trunking.