using bluetooth APIs
there r five APIs for BT.
BT Service Discovery Database ->for self advertisment
BT Service Discovery Agent -> to perform search on Remote Device
BT Socket -> to exchange data.
So in what order I need to use these APIs ?
And do I need to use all of them to make an BT application ?
Take a look at the following page for information on bluetooth application programming:
My two favorites are:
1) Introduction to Series 60 Bluetooth Applications for C++ Developers
2) Designing Bluetooth Applications for Series 60
These documents are specifically for Series 60 development, but they would probably help you with developing for any platform.
You probably also want to go to www.bluetooth.org, get the official bluetooth spec and study it.