In Ubuntu, we use software center to install softwares. Installing softwares in Ubuntu is different than on Mac or Windows; some might say it better. So, instead of going to the web to download a package, it is better to check the Ubuntu Software Center for any program you want to install. The software is stored in a repository which can download easily and quickly.
The best way to download a package/software in Ubuntu is to use repository instead of downloading an EXE file from random websites. In repositories, everything is reviewed by the Ubuntu team, so it is completely safe to download using those. But, you will not find the latest versions of softwares or even Ubuntu itself in the Ubuntu Software center until new version of it is launched.
This is where PPAs are used. A PPA, or Personal Package Archive, is a collection of software not included in Ubuntu by default. PPAs are for non standard software updates. This is basically used by people who want latest versions of the softwares. A PPA focus on an unreleased piece of software. It might include updates for software already in Ubuntu at much quicker rate than Ubuntu itself. So, with this you can decide which software you want to keep up to date. Once done with this, updates will come to you through the Ubuntu Update Manager.
Adding the PPA and installing FreeCAD from the console
Type (or copy-paste) these commands in a console to add the PPA and install FreeCAD along with the documentation:
sudo add-apt-repository ppa:freecad-maintainers/freecad-daily
sudo apt-get update sudo apt-get upgrade sudo apt-get install freecad freecad-doc