The phrase "great importance" means that something is very significant or valuable, and it carries a lot of weight or importance in a certain situation. Full definition
These are of great importance because of its medicinal value. (true-elements.com)
Developing a global perspective is of great importance in today's schools for connecting our classrooms with virtual field trips to other areas of the world. (edutopia.org)
If you work in a technical field or position, then this section takes on greater importance on your resume. (topresume.com)