Links include backlinks and internal links. The other pages that you're linking to on your website and external links are pages that you're linking to off your site. Backlinks are crucial. Getting backlinks directly to your website and directly to your content is essential for ranking. It's one of the top-ranking factors, and it's been one of the top-ranking factors. Internal links it's vital to link to other pieces of your content because it tells website visitors other things they can look at on your website. That's going to help them either expand their knowledge to find other products for sale and give them more resources related to the current resource that they're reading. It's a best practice to link off to other websites who have already put together comprehensive information or excellent information on topics that you're covering as well; there's no downside to doing external links. You don't want to do too many, but there's no downside to linking to other content if it helps expand on and improve the content that you've already created.