What is the use of magnet

A)Magnets are used in a speaker to hold and release the voice. B)You will notice that in the tip of a pair of scissors , there is a small invisible joint magnet.No one told me but I just found it when I was opening a screw then after coming out it stuck on the tip of the scissors. Then I tried it on each one of the scissors I had in my home .The screw stuck in all the scissors. C)Magnets are used in buldozers.While taking out the garbage from the cup of the buldozer,the iron comes out and gets stuck in the buldozer's hand's cup. D)Magnets are used in the computer to collect eligible data from the wavelines. E)Magnets are used to separate the iron fillings from a rusted and broken metal. These are all the uses I know, but if there are more, you can take help from the rest of the population of the country.

Magnets are used in computer to collect data