Depending on which citation style you are using, you will need to differentiate between print and online sources. Each style has its own rules for formatting this information.
For example, you might need to include the online database where you retrieved the information. Including a URL of a journal or website can be appropriate for some citations. Many online sources now include a Digital Object Identifier (DOI) for the text. A DOI is a unique identifier assigned to the online content in order to locate that content on the Internet.
URLs and DOIs are not enough for a citation. You still must include the basic bibliographic information when citing a source.
There are lots of legitimate uses of media for research purposes. Each citation style has rules for how to cite different types of media. Regardless of the format, you always want to include the bibliographic information that will allow others to find your source.
A word to the wise—if your assignment requires you to use scholarly sources, and most of your information comes from blogs, YouTube videos, and websites, you need to Ask a Librarian how to find scholarly books and articles.
Information from those sources will impress your professor in a way that information from websites and YouTube won’t.
Always check your citations against the version of the style manual required by your professor.