An SMS Push is a message to tell the terminal to initiate the session. This happens because you can’t initiate an IP session simply because you don’t know the IP Adress of the mobile terminal. Mostly used to send a few lines of data to end recipient, to the effect of sending information, or reminding of events.
WAP Push is an SMS within the header of which is included a link to a WAP address. On receiving a WAP Push, the compatible mobile handset automatically gives the user the option to access the WAP content on his handset. The WAP Push directs the end-user to a WAP address where content is stored ready for viewing or downloading onto the handset. This wap address may be a page or a WAP site.
The user may “take action” by using a developer-defined soft-key to immediately activate an application to accomplish a specific task, such as downloading a picture, making a purchase, or responding to a marketing offer.
SMS Push uses SMS as a carrier, WAP uses download via WAP.