What is the difference between thick cylinder and thin cylinder?

Hint: As we know that a cylinder is a three dimensional solid figure, one of the most basic of curvilinear geometric shapes. It holds two parallel bases joined by a curved surface, at fixed distance. We know that there are two types of cylinder- thick and thick cylinder. We will understand the difference between the two here.

Complete step-by-step answer:
First we will understand Thick cylinder:
It is a cylinder whose wall thickness is greater than $\dfrac{1}{{20}}$ times its internal diameter. We can say that if the diameter is $20mm$, then its thickness will be $400mm$.

Now in Thin cylinder, the wall thickness is less than $\dfrac{1}{{20}}$ times its internal diameter. We can say that if diameter$ = 400mm$, then the thickness would be less than $20mm$.
Hence this is the basic difference between the thick and thin cylinder.

Note: We should note that a thick cylinder is one whose wall thickness is $7\% $ more than its internal diameter. While in the thin cylinder the wall thickness is less than $7\% $ of its internal diameter. Thin cylinder can only resist internal pressure while in a thick cylinder it can resist internal as well as external pressure.