line type refers to the structure of an internal table,whereas row type is the actual part that contains the data and it refers to the table body.creating internal table using line type and row type concept is for reusability purpose.Line type and Row type are defined at DDIC LEVEL.
Row type defines the header or work area of the internal table where we can hold a record of multiple data type. where as line type defines one field of internal table which can hold only one type of data element.
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