Responsive Web Design
Responsive Web Design Allows Websites To Look Great On All Devices
Responsive Web Design uses a combination of HTML and CSS to resize and move the content around on the web page to make it look good on any screen.
A website that is responsive and mobile friendly looks quite different on a mobile device (phone) then it looks like on a desktop and/or laptop. The width and height, called viewport, of the device you are using plays a major factor.
Go to https://whatismyviewport.com/ see what the viewport is for your device.