All new AdSense for content publishers must complete a two-step application approval process. This approval process only applies to AdSense for content applicants. If you're monetising with a different product (e.g. AdSense for search, mobile, video, games, etc.) then you won't be subject to this two-step approval process.
Here's how the two-step approval process works:
Step 1. We conduct preliminary checks on your website and your details
For the first step, we make preliminary checks on the information that you submitted in your application. This can take up to a few hours. Once we've finished, we notify you by email to let you know whether your application has progressed to the second step of the review process.
Step 2. You place the ad code on your website and we complete our review
Once your application has successfully passed the first step, you need to place the ad code on your submitted website. It’s essential at this stage for you to place the ad code on your website, as the review process can’t be completed until the ad code has been implemented. For help getting started with ad code, please see how to create an ad unit.
Note that live ads won’t appear immediately once you've place the ad code on your website. Until your application has been fully approved, temporary “blank ads” will be shown instead. These blank ads will blend in with the background of the page, so users won’t see them and the user experience won’t be affected. During this time you won’t be generating earnings and if you sign in to your account then you’ll see a red alert banner stating that your account is still under review. This review period also gives us the opportunity to crawl your website and add it to our index so that we can start serving ads as soon as you’ve been fully approved.After you’ve implemented your ad code and we’ve completed our review of your website, we'll make a final decision on your application. This process can take up to several days to complete, so please bear with us while we make all the necessary checks. We'll send you an email as soon as we've made our decision. If you're approved, then live ads will automatically start to show in the ad units that you've placed on your website.