Computer Timeline
Mainframe
Mainframes are used by many businesses and they are probably being used in your life without you even realizing you are on one, for example the police use a mainframe to keep track of all criminal records on their system, because if they didn't have a mainframe imagine how many computers would be needed to store the terabytes of data that they have.
Desktop
Desktops are personal computers usually used in offices, or at home, they aren't mobile but in most cases are more powerful than laptops considering laptops are so much more mobile and less expensive. But desktops can have multiple users like laptops and this is why they are so good for home use.
Laptops
Laptops are desktops thinner and more mobile cousin, they may not be as powerful but they have the the strength of mobility. They can be taken anywhere and this is why the are good for people like entrepreneurs and people who have allot of meetings as they are easy to pack up and to take and they are much less expensive in most cases. However the majority of laptops aren't as powerful as their desktop counterpart.
Netbooks
Netbooks are laptops with even more mobility, the laptop is small and mobile but quiet heavy however the netbook is light AND mobile. But netbooks can be fiddly and irritating with such a small screen, which sometimes wont show a full web page or program and you will have to use a scroll bar to navigate around.
PDA's
PDA's are like small management devices, they can be very useful and were like the first smartphones, if you like as you can access the internet, they are like a mix of today tablets and our smartphones with calls this was a huge leap from old mobile phones and they created the market of smartphones in a sense.
Smartphones
Smartphones are everything we want from a computer in a compact size, we can play games, call text surf the web and do many other things, most people cant find fault in these like Samsung phones and apple's - but there are problems, for example - most smartphones are all glass meaning in most cases, a drop means a smashed screen and they can be £40 depending on the damage, but otherwise they are the apitimy of mobile technology.