ASA mainly has four Gig Ports other than the management. How is it possible to have/configure more than four networks/segments on ASA due to four physical port limitation.
If you have an ASA other than 5505 you can use sub-interfaces for the same.Subinterfaces let you divide a physical interface into multiple logical interfaces that are tagged with different VLAN IDs. Because VLANs allow you to keep traffic separate on a given physical interface, you can increase the number of interfaces available to your network without adding additional physical interfaces or security appliances. This feature is particularly useful in multiple context mode so you can assign unique interfaces to each context.