Old people deliver their massages and communicate with others through letters. This takes many weeks and sometime months. Then telephone came through it we can communicate just in seconds. After little time telephone improves become wireless and called mobile phone. We can carry this device with us everywhere. Now all of us using this technology and benefiting ourselves.
As we says it is wireless so its work with signals. The combination of mobile set and sim card is called mobile phone. Mobile phone is a device which receives and sends our massages in form of digital signals. It is universal and can use everywhere in world. While at other hand sim card contains the information of service provider. In different parts of world different companies are providing mobile services. So we have to change our sim card if we change our region.
At one hand mobiles make our life easy. Now we can communicate with our loving ones at once. But some time we miss or over use this great technology. Some people especially youngsters waste their time in making unnecessary or fake calls. They massage each other without any purpose. They spend their many hours in this mess. We have to use this technology properly.