In Short: In case you want to download Google+ data, following Google's announcement that Google+ is shutting down for consumer use, read on, as we'll explain to you how to do that. The first thing you need to do is visit Google Takeout. This is Google's very own tool which allows you to download data from your Google account (all services, basically), and all you need to do is navigate to takeout.google.com. From there, you will need to select the Google+ data you want to download, but first, you'll need to hit the 'Select None' button, and then select specific services. If you want to get all your Google+ data, you'll need to select: +1s, Google+ Circles, Google+ Communities, Google+ Stream, Hangouts, Hangouts on Air, and Profile options. For some of those options you'll be able to select how the data is stored, so once you do that, you can select where and how to store your data. You can store it as a .zip or .tgz file, while Google can also upload your data to your Google Drive or Dropbox cloud storage accounts, in case you prefer that over regular download (to your computer), which is also available as an option. That is more or less it.
Background: For those of you who have missed it, Google had announced yesterday that the Google+ is going away, well, at least for consumer use. Google will shut down your Google+ accounts and the service altogether on August 2019. Google may have actually been spooked by a recent Google+ data breach, and in addition to that, the company had shared some Google+ usage statistics, and they're quite bad. The company actually lists poor activity on Google+ as the main reason for this move, though there are quite probably a lot more factors included in the mix. Google+ has been around since June 2011, and quite a few people actually prefer it over other social media networks, so the outrage that erupted on the service after Google's announcement was to be expected.
Impact: We're still months away from Google+'s ultimate demise, and even though Google almost certainly will not change its decision, some users are still hoping they can change that via Change.org petition. It remains to be seen what is the next step for Google, as the company will probably launch as service in place of Google+, though nothing has been announced just yet, so we'll see what will happen.