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Difference between a root port and a designated port

Reading through the CCNA books I was confused about the difference between a root port and a designated port. An article on Cisco's website about how STP / RSTP works cleared it up for me. I've copied the relevant info below.

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Root Port Roles

The port that receives the best BPDU on a bridge is the root port. This is the port that is the closest to the root bridge in terms of path cost. The STA elects a single root bridge in the whole bridged network (per-VLAN). The root bridge sends BPDUs that are more useful than the ones any other bridge sends. The root bridge is the only bridge in the network that does not have a root port. All other bridges receive BPDUs on at least one port.

The port that receives the best BPDU is the root port

Designated Port Role

A port is designated if it can send the best BPDU on the segment to which it is connected. 802.1D bridges link together different segments, such as Ethernet segments, to create a bridged domain. On a given segment, there can only be one path toward the root bridge. If there are two, there is a bridging loop in the network. All bridges connected to a given segment listen to the BPDUs of each and agree on the bridge that sends the best BPDU as the designated bridge for the segment. The port on that bridge that corresponds is the designated port for that segment.

A port is designated if it can send the best BPDU on the segment to which it is connected