From Wikipedia: https://en.wikipedia.org/wiki/Business_band
The Private Land Mobile Radio Service (47CFR90, or Part 90 of the FCC Rules) was established in the US in 1927 to permit commercial and public safety uses of two-way radio by commercial entities and non-Federal government agencies. Similar allocations are available in other countries. The available frequencies in the US have traditionally been separated into two pools. One is for industrial and business users, including some special categories such as petroleum, manufacturing and forestry; the other is for public safety including medical, police, fire and others. The industrial and business frequencies, sometimes also known as "business band radio" and the eligibility requirements are listed in 47CFR90.35. Frequencies are licensed on a non-exclusive basis, although fixed stations and mobiles operating in a defined area are issued licenses only following frequency coordination to assure equitable sharing of bandwidth. Anyone conducting commercial business or a number of other activities is eligible for a license.
Other general-purpose two-way radio services with simplified licensing requirements have also been established over the years in the US including GMRS and citizen's band, the latter now being licensed by rule, so that users don't need individual licenses. FRS and MURS are similar pools of frequencies that do not require individual licenses in the USA. There is a similar group of low power, unlicensed two-way frequencies in other countries, such as PMR in Europe and UHF CB in Australia.