What does type=text/css mean?

Question

Question 1 is like the title

Question 2: What is link rel="stylesheet" for?

Answer 1

This is the basic knowledge of HTML. It is recommended to learn these basics first.

Answer 2

Introduce style sheet. The type is text or CSS file

Answer 3

The rel attribute is required and specifies the relationship between the current document and the linked document/resource.

Still don’t understand what rel stands for, what link stands for and what stylesheet is