Question regarding Sell script and Long Exit

Algos, strategies, code
1

Hi All:

This question is on Zerodha Pi
Iam refering to this script I got from Zerodha Expert Advisor


Basically buy when 3ema crosses 15ema and sell when 15ema crosses 3 ema.
In buy script I put tradescript equivalent of 3ema crosses 15ema
In sell script I put tradescript equivalent of 15ema crosses 3 ema.

Now question is instead of Sell script can I put the exit condition in Exit long section …?
What is the difference between Sell script and exit long ?

Thanks in advance
Ramki