After you think a little about that you will see that the use of the headphones determines the kind you're going to be seeking. As an example, if you want to shop for headsets which are small enough to transport them all around you will definitely take a look at ear buds. However, for anyone who is focusing on a task and need to have on the headsets for a longer period of time, a bigger set of earphones will certainly be a good choice.
2. For How Long Are They Going To Be Worn?

Source: http://www.bestheadphonesunder100.net/