Acne vulgaris is the medical name for common acne -- the presence of blackheads, whiteheads, and other types of pimples on the skin. The most common spots for breakouts are the face, chest, shoulders, and back.
Apigee is an API Management tool. If you're interested in API Management systems in general you might find it useful to look at IT Central Station where real users have reviewed many of the options presently available: Best API Management And What Is API Management.
An open API (often referred to as a public API) is a publicly available application programming interface that provides developers with programmatic access to a proprietary software application or web service. APIs are sets of requirements that govern how one application can communicate and interact with another.