In this introductory lecture, some basic features of the spontaneous symmetry
breaking are discussed. More specifically, σ-model, non-linear
realization, and some examples of spontaneous symmetry breaking in the
non-relativistic system are discussed in details. The approach here is more
pedagogical than rigorous and the purpose is to get some simple explanation of
some useful topics in this rather wide area. .Comment: Lecture Delivered at VII Mexico Workshop on Paritcles and Fields,
Merida, Yucatan Mexico, Nov 10-17,199