In one sentence, describe what the following article is about:

Use the link or type "obsproject.com" in a web browser's search bar. Follow the on-screen prompts to install the software. OBS Studio works with Windows 7 or higher, Mac OS 10.9 or higher, or Linux. It's a round, white app icon that contains three comma shapes.  If prompted to review the license agreement, click on OK. The first time you run the app, you'll be asked if you want to run the Auto-Configuration Wizard. Click on Yes if you'd like OBS to guide you through the set-up.  It's at the bottom of the OBS window, beneath the pane labeled "Sources." It's near the bottom of the pop-up menu. The "Create new" radio button, at the top of the dialog box, should be selected.   If you don't want the pointer displayed in your screen capture, uncheck "Show Cursor."  The stream should be enlarged to take up as much of the window as possible. It's in the lower-right corner of the OBS window. The video stream has been saved to your computer. To view your recorded stream, click on File in the menu bar and click on Show Recordings.

Summary:
Go to the OBS Project website. Click on Download then scroll down and click on the operating system you're using. Open the OBS app. Open the video stream you'd like to save. Click on +. Click on Window Capture. Enter a title for the video stream you're capturing. Click on OK. Click on the drop-down menu near the center of the dialog box. Click on the window that contains the streaming video you want to save. Click on OK. Start the video stream, if you haven't already. Click on Start Recording. Click on Stop Recording when you're finished.