In one sentence, describe what the following article is about:

Usually the drain of a washing machine is a pipe behind the machine that the hose on the machine pours into. The hose is sometimes attached tightly to the drain or the hose may simply be pushed inside of it. When identifying where the drain is, you will need to differentiate it from the hot and cold water lines coming into the washer. The hot and cold water lines should be smaller than the drain pipe and they may be marked with the colors red and blue, to show which is hot and which is cold. If your washing machine is draining slowly but it is not completely clogged, you can try simply pouring very hot water down the drain to clear it out. This can release built up soap and scum that is narrowing your drainage pipe.  If you run your washer on hot most of the time, then this may not work for your drainage problem, as you have been doing this repeatedly. However, if you only run cold cycles, then pouring hot water down the drain may be worth a try. In areas that freeze during the winter, drainage pipes can freeze and get blocked up with ice. If your area is frozen and you think you have a clogged drain, try pouring hot water down the drain to get rid of any ice that may have accumulated. If your washing machine drain is clogged, one way to clear it is to use a commercial drain cleaner. In general, these products can be very helpful for minor clogs but have limitations when it comes to unclogging a completely clogged pipe. When buying a commercial drain cleaner, be sure to get one that is safe to use with your specific type of pipes and your type of drainage system. Some strong products that contain sulfuric acid can actually damage PVC pipes and they are generally not good for the environment as well. To use a commercial drain cleaner, you will need to detach the drain line from the machine and put the cleaner straight into the drain. On some machines you can simply pull the tube coming off the machine out of the drainage pipe. On some, however, you will need to unscrew the drainage tube from the machine at the bottom of the back of the machine. If you are doing this, be prepared for some water to come out of the machine and the hose to the drain. This usually begins by pouring the product down your drain with some very hot water. Then you will need to wait a specified amount of time for the product to do its work. Finally, you will need to flush the drain once the product has had time to clear it.  Be sure to rinse out the drain cleaner after the specified amount of time. Leaving it on too long can damage the pipes.

Summary:
Find the drain. Pour hot water down the drain. Buy a commercial drain cleaner. Detach the drain. Follow the directions on the packaging.