The sequence "2, 4, 6, 8, 10, 12, 14, 16, 18, 20" consists of the first ten even numbers. Each number is obtained by adding 2 to the previous number, starting from 2. Even numbers are integers that can be divided by 2 without leaving a remainder. These numbers are commonly used in various mathematical concepts, such as addition, subtraction, and multiplication. They also appear in real-life situations, like counting pairs of objects or organizing items in groups. The sequence is often used in teaching basic arithmetic and number patterns.