what is class limit?

The lower and upper limits of a class interval are known as Class Limits.

class limit is quite a common term used in statisitcs.
it is used to define the highest and lowest value in a class ( or different groups made in the data)
for example
the data of height of teens is collected in a particular locality
so u group the data in following classes
120 - 140 cms
140 - 160 cms
160 - 180 cms
180 - 200 cms
in these groups children with height within a range will be placed in their respective classes
the value 120 is called upper class limit and 140 is called the lower class limit for the first class of 120-140cms