From WordNet (r) 1.6 [wn]:

  context
       n 1: discourse that surrounds a language unit and helps to
            determine its interpretation [syn: {linguistic context},
             {context of use}]
       2: the set of facts or circumstances that surround a situation
          or event; "the historical context" [syn: {circumstance}]

Context helps us to frame information and cast it into something known. When contextualize we allow for comparison which leads to categorization and knowing. If we can provide context with information we can increases the chances of making knowledge.