A Display URL is a type of URL where website address is displayed in your ad. It is denoted with green color next to the “Ad” icon
Display URL gives clarity to the people that which website they are going to reach when they click your ad. Whereas Final URL would be more specific it allows the advertisers to be more specific that on which page he wants to make the customer to land
For example, if your display URL is “www.odmt.in“, your final URL might be.www.odmt.in/AdWords
For expanded text ads, your display URL consists of the domain of your final URL (and the subdomain, if you have one) and your two optional “Path” fields of up to 15 characters each.
Your Display URL always appears in lower case even though you enter in Capitalized letter