Historically originated as a sub-field of topology, knot theory is currently an active area of mathematical investigation. Besides having a high independence, the theory also enjoys strong connections with other areas such as combinatorics, statistical mechanics, and algebra.

In this talk we are going to introduce the first ideas of the theory focusing on the notion of invariants of links. First, we quickly take a look at the historical origins of the theory. Then, we explore the bracket polynomial. Finally, we see how from the bracket polynomial a homology theory can be constructed.