In a social media platform, two users can be represented by nodes and an edge between them that determines some form of professional or personal connection. An undirected edge can indicate that both are friends while a directed edge would mean that only one follows the other in the direction of the edge.

We can use BFS to gain general insights about users such as:

Finding all the friends of all the people in the network.

Finding all the mutual friends for a node in the network.

Finding the nth level friends for a person in the network.

Etc.

In the graph below, we have a social network which has a provision such that two users with ids $1$ and $2$ can become friends when $1$ sends a request to $2$ and $2$ accepts or vice versa. So$,$ if User $1$ and User $2$ are friends, and User $2$ and User $3$ are friends, then with respect to User $1,$ User $2$ is a first$-$level friend and User $3$ is a second$-$level friend. Similarly if Users $4$ and $5$ are friends with $3,$ then with respect to User $1,$ Users $4$ and $5$ are third$-$level friends of User $1,$ and so on$.$

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