An AdWords ad can only have one destination URL where visitors are taken after clicking on your ad. But, in many cases, there are actually multiple pages on your website that could potentially be applicable and relevant to a list of keywords. AdWords sitelinks help solve for that by allowing you to show alternate URL options in addition to your ad's main destination URL. However, they can also distract visitors from your target conversion activity, so be careful when adding sitelinks and monitor results after implementing them.
Brainstorm the additional page URLs you'd like to highlight in your ads. Here are some ideas for pages on your website you can promote via sitelinks: