When you are writing your essay or report, you'll find that you want to include information from sources you have come across in your research. It's fine to include these, as long as you credit the original authors and acknowledge where you found the information.
You will come across a number of sources for information during your research. Only some of them need to be credited in a bibliography.
Have a look through some of these sources of information. Click the ones you think need to be credited in a bibliography: