A dot between two numbers represents multiplication in math. For example, the expression means multiply the number by the number .
Since multiplication is a very common operation in mathematics, there are alternative, short-hand ways of expressing the operation. In elementary mathematics, the (times) symbol is often used, but then later dropped in favor of the center dot, parentheses, or implicitly represented by two variables next to each other.
Two expressions placed next to each other and separated by parenthesis are assumed to be multiplied together.
In mathematics when two variables are next to each other the implied operation is multiplication. This makes many equations and formulas more simple.