What is duplicate content and what does it affect negatively?

Question

I am fascinated by SEO and it's merits, so that's why I am going to optimalize my website. There are still a couple of questions that do pop up... Well, I am aware that duplicate content is not done, but I don't know what duplicate content is for Google... For example, I have a page which links to the top rated posts at the front page... If I click on another page, I do see the same link, but in a different context; not top rated, but just, a regular post... Question: is this duplicate? I have two links that are going to the same post, but is this seen as duplicate?

On the other hand, I have a list of posts that I have ordered in a particular order. Now, I have three links that link to the same post. Besides, I have made an excerpt of the concept with a "read more" to the same post; I have 4 links to the same post... Is this duplicate content? If yes, what should I do? A no-follow on those links?

On the other hand, I have author pages + tag pages in which the same posts pop out. Where do I put a no-follow and why? I would appreciate feedback and help.

Answer 1

Having some amount of duplicate content is expected on every site. Most sites are going to have the same links in multiple places. Sites based on Wordpress and similar CMS systems are going to have the same post on the home page, on the archive page, on the post page, and on each tag page.

Duplicate content hurts the most when it is copied from another site without attribution. Don't take content from another site and publish it on your site where Google can find it without linking back to the original and providing some commentary of your own.

Within your site, try to limit the number of places that large pieces of text content (full posts) appear. If you are running Wordpress, use the <!--more--> tag in every one of your posts so that the full post only lives on the post page and that the home page, the archive page, and the tag pages only get the first few lines.

If you have sort options on a list of items, implement it with AJAX so that there is one page with sortable items on it, prevent Googlebot from crawling too many variations, or use the rel canonical meta tag to tell Googlebot which version is the best one.