Internship is not compulsory for any graduate. But going for intern will have the following benefits:
First, internship help's a student to visualize practically various process that he studied during his theoretical class thereby reducing the gap between theoretical knowledge and practical knowledge.
Secondly, it helps students to learn the environment that prevails in industry.
Thirdly, the student gets to know the various advanced technologies that are presently used.
Fourth, he gets to know the duty reporting of various levels in a company.
Fifth, he is assigned a task given by the company, thereby he learns his time management and the depth in that task.
Sixth, the student has a chance to gain stipend for the task he is doing. (Only some companies provide stipend)
Seventh, the student gains more contacts and friends which will be good for a long term.
Eighth, he gets a value addition in his CV which will reflect during his final placement.