With Facebook’s account backup feature, you can make an offline copy of all your data stored and accessed online on the network.
The information or data that can be downloaded from Facebook’s account backup includes a lot of the same information available to you in your account and activity log, including your timeline info, posts you have shared, messages, photos, and more. Additionally, it includes information that is not simply available by logging into your account, like the ads you have clicked on, data like the IP addresses that are logged when you log into or out of Facebook, and more.
To backup your Facebook data, login to your Facebook account and click on the drop-down icon (downward facing arrowhead) at the top right of your screen, then click on Settings.
Once on the settings page, click on Download a copy of your Facebook data as shown in the screenshot below.
To know more about Facebook account data download and a complete breakdown of the categories of data available to you, click here to access the Facebook help center.