CartoDB is described as 'A location intelligence and visualization engine that empowers you to effortlessly transform data into insights. With CartoDB, connect and map location data, quickly customize your visualizations, and develop powerful location based apps' and is a Map service in the travel & location category. There are more than 25 alternatives to CartoDB, not only websites but also apps for a variety of platforms, including Self-Hosted, Mac, Windows and Linux apps. The best CartoDB alternative is GeoSpy. It's not free, so if you're looking for a free alternative, you could try OpenFreeMap or QGIS. Other great sites and apps similar to CartoDB are VersaTiles, Mapbox Studio, StellaSpark Nexus and Plus Codes.
QGIS is a desktop GIS for creating geospatial data. CartoDB/CARTO is a PAAS for visualizing data.