Plagiarism is where you copy something created by someone else and you pretend it is your own work. You might not mean to pretend you wrote it but if you do not reference your sources how does the reader know you didn't write it?
You need to include the source (hyperlink) underneath the section you have re-written.
It still is not your own original work so you need to credit the original source.
You need to use "quote marks" on the copied parts.
It still is not your own original work so you need to credit the original source.
You need to use "quote marks" on the copied parts.
This is okay for small sections but you should write your own interpretation/explanation underneath so show you have understood it.
There are lots of different ways of referencing your sources and different institutions have different rules. One of the simplest ways is to click on the web address at the top of the browser and copy it then paste it into your document. As a minimum, this allows you to find the information again if you need to reference it in a different way.
Avoid copying links from Google where possible. They are really long and technically, Google is not the source - it is a search engine. What it does it gets short pieces of information from the website that it thinks you might find useful. If you click on the title of the information it takes you to the original source, and this is the link you should reference.
If you are doing general research presentations you do not need to reference the source of your images. Technically you should - especially if it was a professional piece of work - but rules are slightly different for students in school.
If you are producing a piece of assessed work you need to keep a copy of all image sources in an assets table.