What does base mean in 10baseT?

In our number system, we can have columns. We can have a ones column, a tens column, a hundreds column and so forth. The second column determines the base. So a base 10 number system goes 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and then the next number is 10. You can have a base 2 where the second column starts with a 10. It would go 0, 1, 10, 11, 100, 101, 111, 1001, 1010, 1011, 1100, 1101, 1110, 1111, 10000, and 100001. Computers work with base 2 and then translate back to something we can understand. The last number can be 65 or it can be a Capital A, depending on what it is doing.