Scholars often refer to Sisyphus and Meursault as Camus' Absurd heroes. Absurd here does not mean silly or even so much the Theatre of the Absurd often associated with Becket and others. This is Camus' version of Existentialism called Absurdism. Both Meursault and Sisyphus find themselves in seemingly futile and meaningless situations. The Absurdist realizes that the universe is not meaningless but humans are incapable of knowing it. So, to cope with this humans have to choose nihilism, false faith, suicide or acceptance. Camus' Absurdist heroes Meursault and Sisyphus choose acceptance. They embrace their situation and attempt to create meaning for themselves. And in finding meaning, via that search, each must do so individually.
Camus imagines Sisyphus' tragic walk down the hill and likes to think Sisyphus, while tragically aware of his hopeless existence, embraces the futility and with scorn pushes the rock up the hill anyway pretty much in spite and thus, creates his own meaning. Meursault, likewise, scorns the priest, the trial and society in general and chooses being a stranger to stay true to himself as he also embraces the fact that any real meaning that may come to him, must come from himself; not from the social mores or laws of society, no matter what destination this leads him to. They're both tragic heroes, strangers to everyone but themselves.