Switches do not send STP (Spanning Tree Protocol) messages to PCs or end devices. STP is a protocol used by switches to prevent loops in a network by ensuring that there is only one active path between any two network devices. STP operates at the layer 2 (data link) level of the OSI model and is used to identify and disable redundant paths in a network.

When STP is enabled on a switch, it sends BPDU (Bridge Protocol Data Unit) messages to other switches in the network to exchange information about network topology and identify the root bridge. The root bridge is the switch with the lowest bridge ID and serves as the central point of control for the network.

PCs and end devices do not participate in STP or receive BPDU messages. They are simply connected to the switch ports and communicate with other devices on the network through the switch. The switch uses STP to manage its own internal network topology and ensure that traffic is forwarded on the most efficient path, but it does not send STP messages to end devices.

Yes, that's correct. STP messages are sent as broadcasts by switches to communicate with other switches in the network. The STP messages contain information about the switches and the network topology, and are used by switches to elect a root bridge and determine the best path for forwarding traffic.

PCs and end devices do not participate in the STP process and do not receive or respond to STP messages. They simply send and receive data packets through the switch, which uses STP to manage its internal network topology and ensure that traffic is forwarded on the most efficient path. The STP messages are only relevant to switches and are not part of the normal communication process between PCs and other network devices.