Messenger bags are called that because they are the style that were once used mostly by messengers. They first tended to be one large compartment which was large enough so that file folders and large envelopes could fit into it. There was then a choice of slinging the bag across the back while on a bike or walking with it over a shoulder.
These days, messengers bags are typically about the same size but can sometimes offer more pockets or compartments. There are some who prefer the simple style of one principal compartment while others would rather have separate ones for smaller items. Money and keys, for example, are sometimes nice to put in a smaller pocket for ease in finding them.
There are many different styles of bags also. The first ones had a very simple style. They were usually in colors that are neutral, often in black. Now, however, you can find far greater variety. Some are still just as simple while others are quite fashionable. This is a style of bag that can be used by both men and women.
Although you can get messenger bags in other materials, canvas is still quite popular. It is very durable without being really expensive. It is also easy to get in many different colors. That being said, the neutral ones are probably still the most popular, as they will go with any outfit. Men, in particular, tend to prefer muted colors.
If you want an all-purpose bag that can be taken anywhere, canvas messenger bags are worth considering. They are particularly useful if you want to carry paperwork with you, or even a laptop. It’s easy to see why these bags are always in style.