A flowchart is a type of diagram that represents a workflow or process. A flowchart can also be defined as a diagrammatic representation of an algorithm, a step-by-step approach to solving a task.
Its symbols and conventions are standardized by ISO 5807:1985.
Documentation symbols and conventions for data, program and system flowcharts, program network charts and system resources charts (ISO 5807:1985)
https://www.iso.org/standard/11955.html
Flowchart Symbols Defined
https://www.breezetree.com/articles/excel-flowchart-shapes/
Flowchart Symbols and Notation
https://www.lucidchart.com/pages/flowchart-symbols-meaning-explained