Comparing and correlations. This section mentions the following statistics. The bold statistics are more use than the others. String b has bigger numbers that also get bigger regularly. If I asked you which of these strings are like and which are unlike, you might say something like a is like b, c is Different from a.
Strings can vary in length.
Throughout the comparing statistics section of this course, this fact is ignored, and we compare strings of the same length. But computers can not see, and maths and stats deals with numbers. So back to numbers. Our heads can handle differences. The bottom row is the mathematical differences , which are summed on the right.