An ad group is a collection of ads that share common characteristics such as keywords, location, and targeting criteria. Ad groups allow advertisers to target specific audiences based on these shared characteristics. To create an ad group, follow these steps: 1) Create a new campaign 2) Select "Ad Groups" from the left menu 3) Click "+ Add Group" 4) Enter the name for the ad group 5) Choose the targeting options 6) Save the ad group 7) Repeat steps 1 through 6 until all desired ad groups have been created.