How to combine PDFs into one document on Windows and Mac for free

CNET: “Working with PDFs can be tricky, especially if you’re trying to merge multiple documents together. Maybe you’re constructing a portfolio, or maybe you just want to reduce file clutter. Whatever the reason, it can be confusing to keep lots of documents straight, but it’s also tricky to figure out how to bring them together. One of the most popular tools for combining PDFs is Adobe Acrobat, but that software will cost you at least $13 a month for a subscription. Luckily, there are a few other ways you can combine PDFs for free, no matter what type of computer you’re using. Here’s how to combine multiple PDFs for free, whether you’re working on a Windows device or a Mac. (We’ve also got tricks for how to easily sign PDFs, and four free apps for better PDF editing.)…”