Counters are found in many places where you might not expect to find them. Here are a few places where you would see counters.
In a DMM (Digital MultiMeter) a voltage is measured and displayed digitally. Inside the DMM, the A/D (Analog-to-Digital) converter probably uses a counter in the process of converting the analog voltage signal to a digital equivalent.
A real estate agent uses a gadget she places on a wall to measure interior dimensions (distance between walls). The gadget uses a counter to time how long it takes an acoustical signal to travel across the room and return after reflecting off the opposite wall.
You drive across two rubber tubes stretched across the pavement. A counter starts running when you hit the first one, and stops when you hit the second one. That way the police know how fast you were going and tell you that when the ticket comes in the mail.
You can see that there are many places where counters are built into equipment. They are found in many different kinds of equipment and they are devices that you really need to know about.