Different type of Google ad extension :

 There are 9 types of google ad extension :

• Sitelink extension : which can be created manually or automatically— let you add links to specific pages on your website. This gives potential customers more information about your offerings and encourages them to visit the pages most relevant to them. 

• Callout extension : which can be manual or automated—are 25-character snippets of text that extend your ad descriptions. This is a great place to give potential customers more information about your business’s unique selling points.

• Structured snippet extension : manual or automated—let you highlight a list of features or services within your ad. These are similar to callout extensions in that they’re text limited to 25 characters that appear after your ad description. The difference is that structured snippets require you to pick a predefined header from a selection that Google offers, and create a list.

• Call extension : A call extension allows you to add a phone number to your ad, making it easier for customers to reach you. This is a manual extension (although automated location extensions may include a phone number).

• Location extension : Location extensions let you add your business address—manually or automatically—to your ad. They can help customers find you if you operate a physical storefront.

• Image extension : manual or automated—are small square images that qualified advertisers can include in their search ads. (Eligibility depends on ​​account history, ad quality, and adherence to the platform’s advertising policies.) These can be photos of your products or storefront, but they cannot be logos.

• Lead form extension : Lead form extensions—manual only—allow advertisers to include forms and surveys directly in their advertisements in order to collect customer information. 

• Promotion extension : Marked by a price tag icon, promotion extensions let you include information about limited-time sales and promotions in your search ad. You must create these extensions manually.

• App extension : As the name implies, app extensions let searchers on mobile devices download an app directly from your ad. You can only create these extensions manually.