When you Google a topic and use some of the information on various websites you found in an assignment, that information needs to be referenced. You can use our referencing guide to see how to reference websites in your specific referencing style.
You cannot copy and paste images, information, videos, etc. from the internet without proper citations. This includes using images from Google Images or other media sites.
Self-plagiarism is reusing your previous assignments for another piece of work. Self-plagiarism can be tricky to understand. It is possible to plagiarise from yourself, even though you are not "stealing" anyone ideas or work and presenting them as your own - because that's your work, isn't it?
Why is this a problem? When asking you to complete an assignment, your lecturer or tutor is asking you to conduct new research or create a new piece of work. To reuse your old assignments is defeating the purpose and cheating you out of the experience of creating this new research and work.
When you submit assignments to TurnItIn, the assignment is stored and can be scanned for self-plagiarism in the future when you submit new work, and so will be detected for plagiarism when you submit the new assignment.