Every content management platform has its own quirks but with all of them, duplicate content is a potential problem.
Whether you run an ecommerce store or a blog, you have to carefully manage how your site produces content for the web. Without knowing it, you could be creating a significant amount of content duplicated on multiple URLs.
Every page on your site should have unique content, and that content should be displayed on a unique URL. Sometimes, however your content management system leaves you no options. Your content will display on varying URLs, like it or not.
This could be due to using parameters that change a small piece of content (size, color, etc.), or how each visitor navigates your site. These issues can be overcome with good programming. But what if your content management system simply refuses to cooperate without unloading a ton of money on a programmer? You can always implement a canonical tag, which I lovingly refer to as the poor man’s solution.
Canonical tags provide a signal for the search engines, but it’s no guarantee of success. It’s always good as a backup and and certainly better than nothing at all. The best solution is to eliminate duplicate content altogether, but in a pinch, the canonical tag can help.