Make a difference. First you rise, then you fall

Question

With me you can make a difference.

With me reversed, I'll rise and I'll fall.

Answer 1

You are the word:

EDIT - when you 'edit' something (for instance, a post on a StackExchange site, like this one) you quite literally make a difference by altering some of its content.

Reversed, this then gives you:

TIDE - the level of the sea rises and falls every day, as a result of the tide, influenced by the pull of the moon, giving us high and low tides.

Answer 2

A bit of a stretch, but i think you are

Minus

With me you can make a difference.

Is you want to know the difference between two numbers, you will subtract them with a MINUS sign

With me reversed, I'll rise and I'll fall.

The SUN does raise and fall daily and in reverse you clearly tell us "SUN I (a)M"