@shikhasoni1 Metadata profile is metadata schema field set with some default values . So , if a metadata profile is applied to a folder , all assets of that folder will have certain metadata fields having default field values defined in profile.
CSV bulk import is an OOTB utility to update metadata (in bulk usually ) of assets based on assetPath , column values & column header defined in csv. It will updated only assets defined in assetPath column , only update metadata defined in csv column header with specified values.