Goa Dabolim uses 1 terminal common to all flights and internally divided into a large domestic and a very small international section.
The airport is one of the medium sized and very well laid out airports within India.
You can walk the entire terminal in about 5 minutes.
When you enter the airport building from the outside, you have to present your boarding pass or ticket, just show it on your mobile phone.
Transfer between flights
Dabolim Airport is not a transfer hub and therefore does not have a direct trasnfer option.
When connecting, you always have to exit the transit area, walk through the public area to the departure hall, take the escalator to the first floor and go through security.
The total transfer time from a domestic flight takes about 30-40 minutes, while from an international flight it can take more than 90 minutes due to slow queues at immigration.