Why using Notepad.ai
Gradients are CSS elements of the image data type that show a transition between two or more colors. These transitions are shown as either linear or radial. Because they are of the image data type, gradients can be used anywhere an image might be. The most popular use for gradients would be in a background element.
To put it more relevantly, gradients are part of an extremely popular design trend that has been gaining popularity over the last several years. It seems that they have always been around in the background (no pun intended); although, some sources claim that the trend is "coming back". Of course, it's hard for something to come back if it never left, but we'll chalk that up to semantics.
Gradients allow you--the designer--to explore new opportunities to provide fresh, clean design for your audience. The added transition between colors allows you to play with two-dimensional and seemingly three-dimensional aspects, taking your designs from boring to extraordinary with some simple code.
In fact, the best thing about gradient code is that it can be as simple or as complex as you'd like to make it. You can do the bare minimum and let the browser figure out the rest, or you can take things into you own hands and identify all the odds and ends. You could even do a little extra if you wanted and explore the endless possibilities of gradients.