Every programming language handles variables differently. Because length only accepts numbers and name only accepts characters. Instead you have what is known as a scalar variable.
Scalars can contain all types of data.
Floats, Strings, Integers, etc to name a few. Although their variable names stay constant throughout the program, a variable may contain an Integer at one point and then a String at another. For this reason it is VERY important to comment Perl scripts well, because can occasionally get a bit confusing. Scalars begin with a dollar sign and then the variable name. After that you may choose whether to use letters, numbers, or underscores.