Evidence is "Business Intelligence as Code"; which means it allows you to build reports, and standard business data visualization ( charts, and basic graphics) using sql with markdown as the glue between various data and visualization elements. You can put to gether a dynamic report with a few interactive elements (e.g: filter data, change date ranges) that can be exported as "static" web pages. The exported web pages will also have interactive elements (e.g: tooltip on hover, charts that re-render when you change the data criteria). You can see the github; and examples
datasette is another player in this space -- "data applications using sql" space, but evidence goes much further by supporting various data backends, and having first class support for thinking in terms of reports, and standard visualization components like charts. Support for markdown is naturally expected.
The combination of markdown + code does put it in a group with jupyter, but the availability of dynamic controls also make you think of streamlit, but does not go as far as observable because observable, given it's pedigree with d3 etc., is a lot more capable visulization tool (think maps, and advanced dataviz techniques).