SMS (Short Messaging Service) is a text messaging service component of phone, Web, or mobile communication systems. It uses standardized communications protocols to allow mobile phone devices to exchange short text messages over the networks.
MMS (Multimedia Messaging Service) is a standard way to send messages that include multimedia content (audio clips, video clips and images) to and from mobile phones over wireless networks using the WAP protocol.
Email (Electronic Mail) is a system for receiving, sending, and storing electronic messages, Similar to a letter, email is text messages that may contain files, images, or other attachments sent via the internet to a recipient by using applications and software prograps. An email address is required to receive email, and that address is unique to the user.
IM (Instant Messaging) is an exchange of text messages through a software application, it enable you to create a kind of private chat room with another individual in order to communicate in real time over the Internet.