Caps Lock is a feature that you can see in almost all keyboards; when it is active, it capitalizes every letter typed into the keyboard.
Unlike other keyboard keys, these caps lock key is toggle key. Meaning that it is always either in the On position or in the Off position.
When it is off, all the typed letters are always input. At the same time, when it is on, each typed letter is all transmitted to an upper-case character. Caps do not alter lock input like the rest of the keys, such as numbers and symbols.
Since caps lock changes the input of letters into a keyboard, you must know whether it is on or off. Therefore, manufacturers are provided with light to know its active status on the keyboard, which burns when Caps Lock is on. This shows that Caps Lock is on.
Since passwords are often case-sensitive, take care that caps lock is not active when entering any login information. Use Caps Lock only when necessary.