Toggle is a term used in technology to describe the switching back and forth between two settings or options. You can find toggles in everyday technology devices, such as the Caps Lock and Num Lock switches on keyboards, or in software applications that allow you to switch between different display modes or settings.

When you use a toggle, you set a value in the form of a Boolean variable. When a user clicks the switch, it changes the toggle’s state to either “On” or “Off”. You can then check the toggle’s current state and take action accordingly in your program.

Many application developers use toggles to control the features their users have access to. For example, a website might limit its premium functionality to paying customers, or it might disable certain features during periods of high latency. Toggle controls are an excellent way to manage feature availability and to prevent a single bug from breaking the entire application.

Another common use of toggles is to implement multivariate testing (A/B or MVT). By enabling and disabling codepaths with the flick of a switch, you can compare their performance without impacting your existing users.

One of the main challenges with using toggles is that they can be confusing to users, especially when there are multiple toggles in an interface. To help mitigate this confusion, designers often use clear labels to explain what the toggle is doing. They should be short and direct, and limited to a few words at most. They should also be placed above the toggle, not below it, so that all users can easily read them.