1. Virtual Number:
A Virtual Number is a 10 Digit Mobile Number (sometimes also called a Longcode Number) to which your clients or members can send an SMS starting with a keyword.
You will be able to receive the messages in your MSG91 inbox, on your email, and also on your callback URL. You will also be able to set an auto-reply SMS to all the numbers from which you have received responses. Now if you want to send the reply SMS after some calculation on the text received from your client, you will need to integrate the SMS API in your software which will shoot your SMS after the calculation.
For eg. in Kaun Banega Crorepati, you are supposed to send an SMS to 56565 with KBC<SPACE>A/B/C/D
2. Keyword:
If someone sends an SMS starting with your keyword, you will be able to receive the messages in your MSG91 inbox, on your email, or also on your callback URL. So KBC is the keyword. You can choose any keyword for yourself.
You can also set an automatic reply for the SMS you receive.
A keyword of 6 or more than 6 characters would be free of cost. Other than that the pricing would be as follows:
5 Character: 1,000 Rupees
4 Character: 2,000 Rupees
3 Character: 3,000 Rupees
2 Character: 4,000 Rupees
1 Character : 5,000 Rupees
3. Inbox Balance:
That is the number of SMS you can receive in your Inbox. You need to purchase the inbox balance so as to receive the SMS your customer is sending to you.
For a video tutorial refer to this link: https://www.youtube.com/watch?v=kNOb4qApnzw