In real life, there are many things that can have only two possible states, for example, a book is either open or closed, your smartphone screen can be locked or unlocked, power switches at home can be on or off. This holds true for some input and output components attached to BeagleBone as well. For example, LEDs can be either on or off, a push button can be in a pushed state or normal state (often referred to as a closed or open state). These components with only two possible states are digital components.
If you look at the nearby area of the BeagleBone processor AM335X chip carefully, you will see that many physical lines are connecting the processor to various other chips or components on the board. Each of these lines connects to the processor at a point called Ball or Pin. The BeagleBone processor has several such pins to communicate with outside chips and components. Among these pins, some pins are dedicated to deal with digital components only. We cannot attach analog...