To put it simply, responsive is fluid and adapts according to the size of the screen of the device – whatever the target device you are using. Responsive uses CSS media queries to change styles such as display type, width, height, etc. according to the device you are using.
Adaptive design, whereas, uses static layouts depending on breakpoints that don’t respond once they’re initially loaded. Adaptive is an approach to detect the screen size and load the appropriate layout for that device.
If you are interested in Web Development, check out these Web Development Online Courses by Intellipaat.
Also, watch this video to learn more about Responsive Web Design: