When starting a research project you will often need to put your topic in context, often you need to include general statistics, or data that will help introduce your topic. In order to do this, you will need to access reliable data sources (so, NOT Wikipedia!).
For example, you may want to study depression, in which case some broad statistics could be helpful as you set the scene for your research:
In 2016, 4.3% of US adults experienced a major depressive episode (National Institute of Mental Health, 2017).
References
National Institute of Mental Health. (2017). Health and Education Statistics: Major Depression. https://www.nimh.nih.gov/health/statistics/major-depression.shtml
Here are some great starting points when looking for background information and statistics. These are reputable sources that will help you set the scene for your research with appropriate and authoritative information.