Hi,
Depending what country you are from will depend on what grade system you have.
A.B.R.S.M. is the worldwide grading system for the violin and other instruments. Truth is some people find grades good motivational tools and bechmarks others choose not to do them.
The A.B.R.S.M. grades go from grade 1 - 8 with advanced certificates after wards. It usually takes a year or two to take the earlier grades and longer to take above grade 5.
Grades can be great good and a good teacher will be able to get you through them.