Breadth-first search

Breadth-first search (BFS) is the search algorithm that is analogeous to the Depth-First Search (DFS) except that instead of exploring the nodes in to the depth, it explores the neighboring nodes in to the breadth.

Consider the order in which the nodes are explored :

Both BFS and DFS are known to be the methods of uninformed search.  In other words, either method exhaustively searches the entire graph without considering any rules directing to the goal until it finally encounters the goal, i.e. it is not using any heuristics.