The Google +1 button is a feature that users can click to easily recommend and share Web content within their Google network. Google started rolling out the +1 button functionality in 2011.
The button appears next to search results or on websites themselves, if website owners choose to embed it. When a user clicks the button and confirms they want to share the link, the link will show up on their +1 activity tab in their Google profile, making it easier to return to content they found interesting or useful. The +1s are also visible to anyone in their Google network, making it easier to share and recommend information.
The +1 button is similar to Facebook's "like" button, and while it may not be as widely used, it does have its benefits for Google+ users. The more Web content is shared on social networks, the higher it ranks in Google search, so the +1 button is another way that a website can improve its Google ranking and drive traffic to its content.