If you are using a multi-select list field that has many options, you may want to render them inline, meaning that they will be formatted horizontally instead of the traditional vertical alignment. Consider the multi-select list field, Root Causes in the screenshot below. There are many options and the user has to scroll to see them all. 

If the multi-select list field list options setup is changed to inline, the user can see all of the list options without having to scroll and the form is more compact.