The Snowflake PUT command is used to upload files from a local file system to Snowflake stages, but it only supports internal stages, not external stages. According to Snowflake documentation and the community consensus (with BDF having 90% support and multiple verified comments), the PUT command works with: User Stage (B), Table Stage (D), and Internal Named Stage (F). External Named Stage (E) is not supported by PUT - files must be uploaded to external stages using cloud provider utilities. Schema Stage (A) and Database Stage (C) are not valid stage types in Snowflake's stage hierarchy.