greedy means that each pattern will try to match as much as it can.
The pattern /a.*a/ matches as many characters as possible between the first a and the last a.
If your text string is ababacdea, /a.*a/ will match the whole string.
You can control the greediness using a question mark.
The question mark matches a minimum number of times.
The following table shows how to minimize the greediness.
Syntax Means
*? Match zero or more times, minimal number of times
+? Match one or more times, minimal number of times
?? Match zero or one time, minimal number of times
{num}? Match exactly num times, minimal number of times
{num,}? Match at least num times, minimal number of times
{num,max}? Match at least num but not more than max times, minimal number of times