When you succeed at something, you reach a goal or do really well. If you practice speaking Arabic every day, you are likely to succeed at becoming fluent in this language.
When you succeed, you achieve the result you hope for, but another way to use succeed is to describe taking over a position. A prince who will inherit his father's kingdom will succeed his father one day, and a new high school principal can be said to succeed the old one. The Latin root of succeed is succedere, come close after.