Basics on reading Data

What is a data set?
A data set (sometimes referred to as data source, or database) in the context of Tableau, contains the data used to build visualizations. Every bar chart, scatter plot, or line chart you see in Tableau has a connected database or spreadsheet that supplies the data. You can learn more about different data source types.

Spreadsheets
A spreadsheet, such as Microsoft Excel or Google sheets, organizes data in a flat structure, which means the records are stored as single rows of data.

Relational databases
Relational databases store data in multiple tables, with each row assigned a unique identifier. Users pull data from different tables together using Structured Query Language (SQL). The "relational" aspect indicates a logical connection between different tables.

Cloud data
Sometimes, organizations prefer to store their data in the cloud so they do not have to support on-premises servers. This includes data stored in such places as Amazon Web Services or Microsoft Azure.

Other types of connections
Tableau also connects to spatial files for mapping, such as .kml or .shp, and statistical files created in R.