Whenever you cite an article - especially one obtained electronically - you are asked to provide specific information regarding where the information was retrieved from. If you put the wrong information in the wrong spot, the Professor will not be able to verify your sources which could impact your grade on either the paper or the bibliography!
Aggregator (or vendor, if you prefer): this is the company that holds the databases; examples include EbscoHost and ProQuest. There is always only ONE aggregator for the purposes of citing the source. Note: Content from multiple aggregators can live in 'discovery' systems like Molloy's JETfind.
Databases live inside aggregators and the larger aggregators can contain 25 databases or more. Examples of databases within Ebsco would include ERIC, Academic Search Elite, and Business Source Premier. Certain aggregators (e.g. Westlaw, Sage) contain only one database; in these cases they are both the database and the aggregator. More on Databases...
Journals live inside of databases and there could be hundreds of them - they could be periodicals, newspapers, magazines or trade journals. Examples of a Journal would be The Chronicle of Higher Education. Most journals are uniquely identified by an 8 digit ISSN# (xxxx-xxxx). Journals are generally organized by volume, issue, and page number(s). Some databases and aggregators (e.g. Sage, ScienceDirect, PsycARTICLES) contain only peer-reviewed journals, but normally, this is not the case. So, once you have entered your keywords, always make sure to filter for either "scholarly" or "peer-reviewed" results if that is a requirement from your Professor. More on finding journals...
Articles are contained within the journals and of course, there can be thousands of them. This is the bottom level that leads to the full text. The article level is what you see in the results page after you enter your keywords, but the Journal, Volume, Issue and Page Number(s) are always contained in the article’s abstract or citation. The DATABASE is normally indicated somewhere at the top of the page. All of this information is required in order to cite a journal article. More on finding articles...
Simply stated - this time from the bottom up: articles live in the journals, which live in the databases, which are accessible via an aggregator. Knowing the names and the components will help you keep your citations and your research organized.