Number sequence limit (mathematics)?

Question

Mathematics

What does this number "ℇ" mean? It seems that I understood everything, but what it is is not clear.
"Number Sequence Limit" on wikipedia .

Answer 1

This is, relatively speaking, some variable. Whatever its value you choose = whatever range you take, large, small, - starting from some number of the sequence member, all further ones will lie in this range relative to the limit.

Answer 2

ℇ - measure of proximity - the difference between the current value and the limit.