On Mobile devices.
On a mobile device they all have different features, some have just texting and call(normally the older phones) some have wifi, memory, camara etc. Many of the newer phones have more features. In the olden days they only had texting and calls. Nowadays you get plenty more features on different phones.
The Different Features;
-Roaming;which permits the same phone to be used in multiple countries, providing that the operators of both countries have a roaming agreement. -send and receive data and faxes (if a computer is attached), access WAP services, and provide full internet access using technologies such as GPRS. -Applications like clock, alarm, calender and calculator and a few games. -Sending and receiving pictures and videos through MMS, and for short distances with e.g. bluetooth. And plenty more.