Yoga development really is an ongoing and endless process. There is so much to learn.
Workshops range in length and type.
Ranging from 3-4 hrs a half day workshops are usually a more detailed class, designed to look at something in detail or give an intensive experience.
Courses offer a longer learning experience. This type of workshop may have a certificate attached and have more complex ideas or be designed to have two halves.
Longer trainings such as teacher trainings or CPD (continued professional development) are also offered. These are usually registered with yoga alliance and are a professional qualification. Follow link to post graduate workshops.