Many a times as a surfer you might have come across more than one site having similar content. Even as a website owner you might have been concerned about your content being copied. Google on their official webmaster central blog explains the pros and cons of duplicate content.
Google blog quoted, “Duplicate content generally refers to substantive blocks of content within or across domains that either completely match other content or are appreciably similar.” According to them an article written in Spanish as well as English is not duplicate, moreover, quotes or small phrases are also not considered as duplicate.
Google further voiced their concern over duplicate content. They said, “Our users typically want to see a diverse cross-section of unique content when they do searches. In contrast, they're understandably annoyed when they see substantially the same content within a set of search results.”
Many people are unaware that they can file a DMCA request to establish their rights over their content, when used inappropriately by other sites. Google's webmaster also clears many other doubts by addressing duplicate content related issues on their blog.