Any Specific difference you are looking for? Otherwise there are so many differences.
Grid is column represenatation while in Scroll area user have liberty to place fields etc..

Thanks
Nitin

thanks for your reply.
just i want to know 3 or 4 differences between grid and scroll

The scroll area, like a grid, is a way of grouping multiple fields of data.
The fields in your scroll area can be placed randomly, one on top of the other as well as side by side.
Unlike a grid, you are not limited to the type of controls you can place in your scroll area. You can even place a grid inside a scroll area.

And according to PeopleBooks, here is why scroll area is better than a scroll bar:

Overall, a scroll area provides you with a wider range of functionality than a scroll bar. There are several options you can choose for a scroll area that you cannot use for a scroll bar. Also, some of the scroll areas enhanced features make designing pages easier for you and the runtime product more intuitive for the user.

* The navigation tools you select for a scroll area are automatically positioned on the navigation bar or footer bar. With scroll bars, you have to place these buttons and links manually on the page.
* Scroll areas give you the option of showing or hiding a border around your data.
* Scroll areas provide the option of a View All button and a Find feature.
* Scroll areas allow you to determine the text or image that displays for the action items in the navigation bars.
* Scroll areas provide a row separator when you select multiple occurrences of data.

good enough but this is not clear difference more for scroll and nothing for grids

Using Grids you can have a tabular representation of the data but Scrolls can represent the parent child relationships.