Which feature applies to the Google Display Network, but not the Google Search Network?
A) Language targeting
B) Frequency capping
C) Location targeting
D) Cost-per-click (CPC) bidding
Frequency is the average number of times a unique user sees your ad in a position of “1” over a given time period. Use frequency capping to help control the maximum number of times that you’d like each person to see your ad on the Display Network.
Read more here: https://support.google.com/adwords/answer/117579?hl=en