Databases are searchable indexes of the research articles in journals. They do not house the articles themselves, but will usually link to where you can find the full text. Look for the blue "find it at UF" button! Some of the most useful databases to get started with for chemistry are the following:
Reaxys is a chemical literature database that allows for searching by structure, property, or bibliographic field. It combines the Beilstein and Gmelin compound databases, as well as a patent database. There are also a number of video tutorials hosted by Reaxys to get you started on using the database.
Web of Science is a general science database best known for its citation searching capabilities. It has good coverage of chemistry, but mostly limited to articles from core journals. It's an excellent choice of database for general searches to survey your field. This database can also help you study how an idea has evolved over time.
Other chemistry-related databases
PubChem: A free access database of chemical molecules and their activities with biological assays. This database is maintained by the National Center for Biotechnology Information underneath the National Institutes of Health.
PubMed: A free index of biomedical information hosted by the National Institutes of Health. SciFinder will search much of the PubMed index, but does not include the most recent entries. Additionally, PubMed has a variety of limits you can set which you cannot set in SciFinder (e.g. Clinical Trials, Phase I; Human vs. Animal studies, etc.).
Protein Data Bank (PDB): The PBD is a freely accessible database of 3D protein structures, containing data submitted by biochemists and biologists worldwide. Free software, including UnityMol and VMD, can be used to visualize protein structures.
BRENDA: The Comprehensive Enzyme Information System (called BRENDA) is a free to access, comprehensive repository of enzyme data. It is particularly useful for gathering enzyme kinetic data.