1. A method for providing information about a main knowledge stream using an apparatus for providing the same, the method comprising: obtaining, at an information process module of the apparatus, reference links representing reference relationships among reference documents for each of a plurality of documents stored in a database; defining, at the information process module, one or more paths connecting the reference links for each of the plurality of documents; determining, at the information process module, a longest path among the defined paths as a basic path for each of the plurality of documents; calculating, at the information process module, probability values of the reference links by overlapping the determined basic paths; determining, at the information process module, a first document from among the documents and an input reference link for the first document, and performing at the information process module, a Markov chain model using a probability value of the input reference link; and calculating, at the information process module, the information about the main knowledge stream for the first document using a result obtained by performing the Markov chain model.