BB Guns versus Airsoft Guns

What is the difference between a BB gun and an Airsoft gun?

In short BB guns (airguns that shoot a steel or lead BB) have been around for a long time so they get to keep the name of being called a "BB gun", even though many people refer to Airsoft guns as "BB guns". And yes Airsoft guns shoot a plastic BB but they do not inherit the name as it is reserved for the long standing… well BB gun!
BB guns generally shoot a 4.5mm or .177 caliber steel BB but some can also shoot lead BB's.
BB guns are most often used for target practice and training, some high power BB guns can also be used for pest control.

Read full article here:
https://www.replicaairguns.com/2012/7/9/bb-guns-versus-airsoft-guns-pros-cons.html