In all fairness, Waiting for Godot can hardly be summarized. One wag did it this way: "And it came to pass, nothing came to pass." Cliff's Notes, that erstwhile Bible of literary students, offers this:
The plot--i.e., the sequence of events--is not at issue here. What matters is what the director does with the plot--and setting, and lighting, and characters, and costuming. The main issue may be futility; it may also be security based upon the predictability of daily existence. Or it may be farcical hilarity engendered by the uselessness of unthinking repetitiousness in a world of brilliant, but unrealized, possibilities. Or anything in between.
In a black-and-white world of ragged tramps, on the assumption (denied by Beckett) that Godot signifies God, this play has been called the ultimate existential tragedy--if such is possible. (In the language of the play, French, God--or Dieu--in no way resembles Godot. It is only coincidental that English shows a connection.) In a colorful world of unimaginative repetitions, it may be boring or pitiful or hilarious, depending upon the characters' attitudes of "that's all there is, folks," "shouldn't there be more," or "ain't it grand?" Or in a magical world of potentially unlimited possibilities, it might be the quiet exhilaration of enduring transitory, though incomprehensible, trials.
A major obstacle to agreement on what is happening and why, is the nebulous identity of Godot. Some critics say "an entity"; others settle for an abstraction. Some identify him with God; others insist on a-sexual, a-physical, a-spiritual idea-ness. Beckett himself said if he had known who or what constituted Godot, he would have said so.