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

Go to https://play.google.com/books in your computer's web browser. This will open a list of books which you own on Google Play if you're logged in. If you aren't logged into your Google Account, enter your email address and password when prompted before proceeding. If you don't have any books in your Google Play Books library, you'll need to purchase one before you can download it:  Type an author, title, or keyword in the search field at the top of the window. Click on a book. Click the price (or FREE) at the top of the window. If prompted, confirm your purchase by entering your password and any requested payment information. Scroll through your list of books until you find the one that you want to download.  You cannot download book samples on desktop. If you purchased a book, first click My books on the left side of the page. It's in the lower-right corner of a book's icon. Doing so prompts a drop-down menu. Samples cannot be downloaded to desktop. Click either Download EPUB or Download PDF in the drop-down menu. Clicking either option will prompt the eBook to download in ACSM format. Depending on your browser's settings, you may first have to select a save location or confirm the download. Since both the PDF and the EPUB option result in an ACSM file being downloaded, you'll need to turn the ACSM file into a readable PDF. To do so:  Go to https://ebook.online-convert.com/convert-to-pdf/ in your computer's web browser. Click Choose file near the top of the page. Select your eBook's ACSM file. Click Open  Scroll down and click Convert file  Wait for the conversion to finish. The PDF will download automatically after the conversion is complete.

Summary:
Open the Google Play Books website. Purchase a book if necessary. Find your book. Click ⋮. Download the book. Convert the downloaded file into a PDF.