Abstract: This is the second part of a pedagogical introduction to the theory of buildings of Jacques Tits. We define a(B,N) pair and construct a building out of it. Then we give a description of Chevalley groups, their(B,N) pair and the associated buildings. We illustrates this theory with many examples from classical groups. 

Key words: (B, N) pairs, Tits system, Chevalley groups, classical groups, Buildings, , flag , varieties