House loading, which may be perceived as a construction process), while most of them are created in a general 'any-use' form (for example, most popular chasing arrows spinner. There are some animations (like Growing ring), that form a circle in one or another way during animation. More than 1000 free and premium ajax loader (loading animated GIF, SVG and APNG) spinners, bars and 3D animations generator for AJAX and JQuery circle loading animation. The 'circular' category mostly consists, but is not limited to spinners. It has become quite a standard and even non-IT professionals understand that they need to wait for a process to complete when the spinner is shown.
This kind of illustration is considered most optimum as, usually, it doesn't take a lot of interface space, does not usually require a lot of frames (making it lighter in terms of bytes), while clearly shows that some action is being taken on the background. Mostly these animations are placed in a transparent square image. Sometimes it is referred to as a throbber or a round pre-loader.
A loading spinner or a spinning pre-loader is an image (usually animated) in which an object or a set of objects spin around some axis indicating a content loading process.