Facebook’s Like button’s popularity is ever increasing and now it is almost ubiquitous on the Internet. In light of this fact and to take over some share of social recommendation from Facebook, Google has introduced +1 button. The +1 button can be seen on the search results page. Google soon plans to let people add it on their websites as well.
Google in its own words says:
The +1 button is shorthand for “this is pretty cool” or “you should check this out.”
The +1 button can make it easy for you to find the things you’re looking for. You should be logged in to your Google account to see the +1 recommendations from your friend. All your +1s are stored under the +1 tab on your Google profile and you can opt to show it to the world or set it as private from Google profile settings.
Here is a video from Google on +1 button.