1. Download and Install OBS
Download OBS from https://obsproject.com/download and install according to the instructions for your OS.
When you launch OBS you should see something like this (with a different look depending on your operating system):
2. Screen Recording Quick Setup
OBS uses a system of Scenes and Sources, which we'll go into more detail on in a subsequent tutorial. These two features work together to neatly manage your video, audio, and other production assets. When you first launch OBS you'll see there is already a scene added in by default, which you can find in the bottom left corner of the interface.
Select Screen Capture (Linux) or Display Capture.
Before you can start recording you'll also need to add a source inside this scene. With the default Scene selected (it will be highlighted) click the + button at the bottom of the panel labelled Sources, then select Screen Capture on Linux or Display Capture on Mac and Windows.
Click OK on the box that pops up.
Click OK on the next popup as well.
In the same procedure, add a Video Capture device and select your camera. Position the camera on your screen.
Now click the Settings button at the bottom right of the interface.
Choose the Output tab and take note of the Recording Path field. This is the destination of your computer where your recorded video will be saved.
Also, change the Recording Format to mp4.
3. Start Recording
When you're ready to start recording click the Start Recording button at the bottom right.
When you're done click Stop Recording and a video will be written to the folder specified in your settings.