Dear Student,
1) There are many types of switches. Among them main are:
(i) Toggle switch
(ii) Push button switch
(iii) Rotary switch
(iv) Proximity switch
2) Two way switch is used to control same device from two different location. It is like you can light the same bulb from two different location using two way switch.
3) The main use of indicator is to show the presence and absence of something. In circuit, indicators are used to check the flow of current.
Regards,