Routing is used to find the shortest distance between the different nodes from source to destination. Routing is basically used to find the efficient path to send the packets from source to destination. In the traditional technique, the main focus was on the distance. But as the time passes, so many issues took place which becomes a hindrance for achieving efficient routing in WSN. This study provides an overview to the concept of routing. The type of routing is also discussed under this in section 1. Section 2 represents the various issues and challenges that falls on the way to achieve effective route for data transfer. Section 3 represents the concept of trust based routing, in which all the trust models are defined in brief along with their pros and cons. Section 4 represents the work that already had been done in this work. Section 5 is winding up of the study by presenting the whole research in brief.