It's to give the authority to the corporation to enter into any legal transactions an individual could enter into that aren't essentially activities only a human being could enter into—for instance, adopting or getting married. That is the power: it's to give the power to engage as a legal entity, and it's quite common to give this to crown corporations.
Elle donne à la société le pouvoir d'effectuer toute transaction juridique qu'un individu serait susceptible d'effectuer, hormis les activités étant la prérogative des seuls êtres humains—l'adoption ou le mariage, par exemple.