The alcohol in your drink is absorbed into your body through the stomach and small intestines. Food slows down the rate of absorption - that's why alcohol affects you more quickly when taken on an empty stomach.
Alcohol travels through the intestines to the liver and then on to your heart, brain, muscles and other tissues. This happens very quickly - within a few minutes. Usually, though not always, this has a pleasant effect.
Your body can't store alcohol, so it breaks it down - your liver’s job. The liver firstly changes alcohol into acetaldehyde (this is toxic), then into acetate (harmless), which is then broken down into carbon dioxide and water. About 90% - 95% of alcohol consumed is broken down by the liver, 5% - 10% is excreted through urine, breath and sweat.
Your body's ability to process alcohol depends on your age, weight and sex. Your body breaks down alcohol at a rate of roughly one drink per hour.