An empirical (AKA original research, primary research) article is a piece of research that provides original data from a specific study designed by the authors. In PubMed, you'll see these described in categories like Clinical Trial, Evaluation Study, Comparative Study, Randomized Controlled Trial, and other articles that are categorized as a "study" or a "trial". For example:
Dodd, J. M., Deussen, A. R., & Louise, J. (2019). A randomised trial to optimise gestational weight gain and improve maternal and infant health outcomes through antenatal dietary, lifestyle and exercise advice: The OPTIMISE randomised trial. Nutrients, 11(12), 2911. https://doi.org/10.3390/nu11122911
Yang, Q., Hatch, D., Crowley, M. J., Lewinski, A. A., Vaughn, J., Steinberg, D., Vorderstrasse, A., Jiang, M., & Shaw, R. J. (2020). Digital phenotyping self-monitoring behaviors for individuals with Type 2 Diabetes Mellitus: Observational study using latent class growth analysis. JMIR mHealth and uHealth, 8(6), e17730. https://doi.org/10.2196/17730
A review article is a piece of research that aggregates and summarizes other researchers' works to provide a fuller picture of the overall knowledge on a topic. (i.e., Not their own original research, but a discussion of others' original research.) In PubMed, you'll see these described in categories like Systematic Review, Meta-Analysis, and Scoping Review. For example:
Perales, M., Santos-Lozano, A., Ruiz, J. R., Lucia, A., & Barakat, R. (2016). Benefits of aerobic or resistance training during pregnancy on maternal health and perinatal outcomes: A systematic review. Early Human Development, 94, 43–48. https://doi.org/10.1016/j.earlhumdev.2016.01.004
Baldoni, N. R., Aquino, J. A., Sanches-Giraud, C., Di Lorenzo Oliveira, C., de Figueiredo, R. C., Cardoso, C. S., Santos, T. R., Alves, G. C., Dal Fabbro, A. L., & Baldoni, A. O. (2017). Collective empowerment strategies for patients with Diabetes Mellitus: A systematic review and meta-analysis. Primary Care Diabetes, 11(2), 201–211. https://doi.org/10.1016/j.pcd.2016.09.006
