In research, its not uniform across all shops.
Associate almost always includes the post MBA people, who do not have their own coverage.
Analyst is the official title of people with their own coverage at my shop.
Then we all have internal positions. For example, I am an associate on my business card, but i am an analyst, in that I am just over a year out of school and a part of the investment banking analyst program.
And senior analysts have the typical internal titles (VP, MD, etc..).
The easiest way to figure it out is if it requires and advanced degree or 3+ years of work.