Fig. 2
From: EpiViewer: an epidemiological application for exploring time series data
Architecture of EpiViewer. EpiViewer is developed as a three-tiered architecture. The Presentation Tier includes the user interface and application functionalities, and communicates with the business tier via an API layer. The Business Tier contains the core logic of all major application functionalities (e.g. upload data, data sharing). The Data Tier consists mainly of the relational database storage. Data can be loaded into the system via the user interface or externally via services from the API layer