Application Programming Interfaces (APIs) are constructs made accessible in programming languages to enable developers to enhance advanced usefulness without difficulties. They take the more unpredictable code away from you and replace it with a simpler phrase form. If you need to use an appliance in your home, you simply plug it into an adaptor and it works. You don't attempt to connect it directly to the power source - it would be wasteful and, if you aren't a circuit repairman, complicated and dangerous.