A mobile ad hoc network (MANET) incorporate mobile wireless nodes, the communication between these is carried out without any centralized control. MANET is a self organized and self configurable network where the mobile nodes move arbitrarily. The mobile nodes as a router receive and forward packets. Routing is a critical issue in MANET and hence the focus of this work along with the performance analysis of routing protocols. In this work, the evaluation and study of four routing protocols i.e. AODV, DSR, OLSR and TORA is done on the basis of the mobile node mobility factors, traffic sources and traffic loads. The simulation tool used is OPNET modeler version 14.0. The performance of these routing protocols is analyzed using three metrics: packet end to end delay, routing overhead and throughput. All the four routing protocols are compared, analyzed and explained in a detailed manner with metrics.