The main aim of designing a responsive website is to have a single website, but with different web elements and components that respond differently when viewed on devices of various sizes.
To understand in a better way, let us take a standard “fixed” website. When displayed on a PC, for example, the website may display 3 or more columns. However, when you switch to or visit the same website on the different device with a much smaller screen size that very same layout will break or the device would force you to scroll horizontally, one thing users don’t like. Or some of the web element could be hidden from being displayed or sometimes look distorted. The impact is also sophisticated by the actual fact that a lot of websites are often displayed either in portrait orientation or turned sideways for landscape view in the devices like tablets and smartphones.
On a small smartphone screen, websites are often challenging to display in the correct proportion. Larger pictures on the website could “break” the layouts. Websites are often slow to load on smartphones if they are loaded with animation, high file size images and graphics.
This won't be the case if your website uses responsive web design. A website, when viewed on a tablet, will automatically fit to the screen size of the device to display simply 2 columns. To ensure that the content is clear and simple to navigate. On a smartphone, the content often appears as one column or maybe stacked vertically. Or presumably, the user would have the flexibility to swipe over to look at different columns. In responsive web design, the images are often can resized to screen size to avoid distorting the layout or getting cut off.
Most of the times, responsive website and its design elements use fluid grids. All webpage components and web elements are sized by proportion, rather than pixels. Let us say if you want to display 3 columns proportionally across various screen size. In this case, you can't say precisely how wide each element should be. This is where responsiveness comes into play, rather you can decide how wide or long they must be displayed in relevance to the other columns. For example, if you have a 3 Column, then you can design in a way that the first column should take up half of the screen space. Likewise, the second column should take up 30% of screen space, and the third column should take up 20% of the screen space. If you design in this fashion, your website will be displayed seamlessly without any distortion across various screen size. Most of the web designing course teaches designing a responsive website by default conforming to the current trend.