My Activity page, is a new page launched by Google, which gives you a detailed overview of everything you've done on Google, ever (provided you haven't explicitly forbid Google to accumulate this data).
This includes your Chrome browsing history, search queries on Gοοgle, image searches, videos you've watched on YouTube etc. The history is searchable, and you can also filter it by date and product. It basically contains your entire online life. But that is not the only change related to Gοοgle services! It seems that Google's ad tracking has been expanded as well and they do give you the option to turn it off. Gοοgle is using the data that its been gathered from you in order to give you better targeted ads. As the company wrote for its users: "When you use Google services like Search and YouTube, you generate data — things like what you’ve searched for and videos you’ve watched. With this change, this setting may also include browsing data from Chrome and activity from sites and apps that partner with Gοοgle, including those that show ads from Google." You can turn off "ads based on your interest" as well as "ads based on your interests on websites. It will be turned off by default, and users will be offered an option to turn it on. But even if you turn both options off, you will still be able to see ads, but these ads will be less relevant, and unrelated to your interests and previous visits to other sites. Users will get a notification to review their privacy settings as the new features become available soon enough.