Index range scan

Dear experts,

I am going through this statement multiple times but i am not clear about this. I sincerely request you to please make me understand this statement.

access predicates are much more preferred if they can replace filter predicates. The reason being that filter predicates usually happen after you get the data, while access predicates determine how you get the data. This can be showcased by an inappropriate range scan; if you have an index with 3 columns and the query only specifies column 1 and column 3, the optimizer has to do a range scan for column 2. If the query can be adjusted to included column 2, the optimizer no longer has to do a range scan, and can move the filter predicate to an