Many people know that they need a bag to hold things, but the choice will be at a loss. One of the biggest questions is: "What is the difference between a briefcase and a messenger bag?" The answer to this question may vary from person to person. However, this is a big move.
Historically speaking, briefcases were carried by carrying hands. This is a bag often used by lawyers to carry legal briefs, so it is a "briefcase." It must be large enough to hold legal-sized documents and protect them. A long time ago, it was common to see hardware/locks in briefcases. Some people still do. Of course, this is a bit impractical, because you can easily break it down into one if you want.
The general idea of briefcases is to use more formal bags in legal, banking, sales, business and similar situations. It is usually a more regular-shaped bag that will not sag.
On the other hand, the crossbody bag is slightly looser and can be placed on the shoulder or crossbody bag. Usually, it is carried by postmen, couriers, etc. It may be a softer bag, usually not as large as a briefcase, and usually does not have a handle. Getting in and out of it is also fast-security is reduced a bit.
Over the years, the boundaries have been blurred. Changes in technology and increased consumer demand make it more difficult to distinguish this difference. However, some rules still seem to hold. For example, if you are going to wear a suit, you probably should have a briefcase. The messenger bag that carries a suit is a bit like a sneaker in a suit.
Most importantly, you must choose what you like and want to carry. Of course, the bag also needs to meet your functional requirements.