营改增后借款利息发票:associate professor 和assistant professor有何区别？

下面这个答案非常好，可我要问的是另一方面。
我国现行的“副教授”一职，在英语表答时，有人用associate professor
也有人用assistant professor。那么在西方国家该如何表述“副教授”呢？
另外，这两个词在英美两国是否有所区别？

Let's use lay terms to understand the differences. When we apply for a job, the position may be a temporary contract job for 6 months. It may be a permanent job forever, but we must pass the probation first.

Temporary position for professorship is an adjunct professorship. Sometimes, a full time well known professor from a famous university can go to another university to join a research program for a few months to a few years. Anyway, all adjunct professors are temporary.

An assistant professorship is an entry level position for new PhD graduates. He/she must work hard to produce enough research publications to obtain his/her tenure, like passing a probation.

An associate professor has passed his tenure (probation) and is a full time permanent staff, though his position is still junior.

A professor is a tenure permanent full time staff and is more senior by promotion.