When you turn on Campaign Optimization, you select optimization guidelines, which help you spend your campaign monthly budget on the ads that best meet your goals and objectives. Just set the value and relative importance levels for the guidelines that are relevant to your business. These settings will be used by the ad groups in your campaign, unless you set custom values for them.

Note: If Campaign Optimization is on, you can't change an ad group's Sponsored Search status, Content Match status, or match type, or set an ad group bid because Campaign Optimization manages the distribution tactic, match type and bidding for you.