The tags which are provided in JSP may not be solving the total problems of JSP programmer. In some situations, there is a possibility of repeating the same code many times by various JSP programmers and it leads to poor performance of a JSP application. In order to avoid the repetition of the code, it is highly desirable to develop the code only one time in the form of tags and use these tags by other JSP programmers. These tags are known as custom tags.
Advantages of custom tags: