Difference Between Push SMS & Pull SMS
In simple words, When someone sends you an SMS, that means he/she pushing SMS to your phone. When you are requesting for some SMS from a sender and you have received the same, then you are pulling the SMS from the sender to your phone.
Push SMS
Any/all kinds of message originating from the server without a request from the receiver/mobile subscriber is defined as PUSH SMS.
Example: You get a SMS about offers or announcements from a bank OR getting a balance info SMS when you withdraw money from a bank ATM etc.
Pull SMS
Any/all kinds of message originated from a mobile device and received at the server end and server responds with an available information, then it is a PULL SMS.
Example: You are checking a live score by sending a request to 556677 OR you are checking an account balance of your bank account by sending your account number to 556677 etc.
The pull SMS are of 2 types - 1) Short Code and 2) Long Code
Short Code : The short code is a short number (56677) to which the customers can sent a message to fetch any information. The outgoing message from your phone is generally charged at premium rates when a Short Code message is initiated.
Long Code : The long code is generally a mobile number (9895012345) to which the customers can sent a message to fetch any information. The outgoing message from your phone is generally charged at local rates when a Short Code message is initiated.