Keycard

     Everyone can find a key card using in daily life. The benefit of using a key card is to limit the people to access to something, which is important to the majority life nowadays.

There are many ways to use a key card system, the business sectors mostly use a key card for accessing a door or use it as a identification card for employees. You can usually see the key card system in a hotel, condominium, apartment, office, etc.

In my experience. I have key card for using the elevators in my dormitory and use to access the room also. It is useful in terms of security. People outside who do not have a key card cannot use the elevator and access the building.

However, It still has some problems from using a key card. It creates inconvenient to keep the key with you all the time. In case that you have lost or forget a key card, you cannot access your room anyways.