Final answer:
Bridges in computer networks prevent cycles from causing endless loops by using a spanning tree algorithm, such as the Spanning Tree Protocol (STP). STP designates a root bridge and blocks redundant paths to ensure there are no loops in the network.
Step-by-step explanation:
In order to prevent cycles from causing endless loops in a network, bridges in computer networks use a spanning tree algorithm. This algorithm ensures that there is only one path between any two points in the network, preventing loops. One popular algorithm used for this purpose is the Spanning Tree Protocol (STP). STP is an IEEE standard and it operates by designating one bridge as the root bridge, and then each bridge in the network determines the shortest path to the root bridge. Any redundant paths are blocked, ensuring that there are no loops in the network.