Irrespective of the types of plagiarism, ultimately plagiarism is a punishable offence. Therefore, it is a good idea to get fully acquainted with the different types of plagiarism in order to be able to effectively avoid difficult situations. You are best advised to err on the side of caution and therefore credit too many authors and originators rather than not crediting others enough. Plagiarism is not a trivial offence, but theft and will be treated as such, irrespective of whether or not you plagiarise intentionally or unintentionally.