In the general sense of purpose and function, there is no real distinguishing between a ‘salve,’ a ‘balm,’ and an ‘ointment’ – all three terms can correctly be used interchangeably.
The Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, in fact, (that is an absurdly long title, by the way) officially defines an ointment as “a semisolid preparation for external application to the skin or mucous membranes, [that] consists of medicinal substances incorporated in suitable vehicles (bases). (Called also salves and unguents).”
In less clinical, easier-to-understand terms, a salve (or balm or ointment) is a medicine-infused concoction (in our case, of course, CBD is the medicine) that are administered directly through the skin.
Regarding CBD creams and CBD lotions, the only real difference between them and salves/balms/ointments is that creams and lotions use a bit of water and moisturizing agents in their bases; salves and balms only use fatty oils and wax as a base, with no water. Of course, this accounts for a difference in texture more than anything else – the real functional differences, which we’ll talk about in just a moment, lie more in the specific ingredients used and the amount of CBD present in the salve.