Nearly all research builds on previous research. Researchers commonly begin a project by studying past work in the area and deriving relevant information and ideas from their predecessors. This process is largely responsible for the continual expansion of human knowledge. In presenting their work, researchers generously acknowledge their debts to predecessors by carefully documenting each source, so that earlier contributions recieve appropriate credit.
As you prepare your paper, you should similary seek to build on the work of previous writers and researchers. Whenever you draw on another's work, you must also document your source by indicating what you borrowed-whether facts, options, or quotations-and where you borrowed it from.