All cells use DNA as a code for making proteins: the sequence of base pairs in a long, string-like DNA molecule acts as a set of instructions for making a protein, which is also a long, string-like molecule (made up of amino acid building blocks).
However there is a middle step as well. Instead of the DNA code being directly used to make proteins, the DNA code is used to make a molcule of RNA (which is structurally very similar to DNA). This RNA molecules contains the same code as the original DNA, and it is this which is used by the cell to make the protein molecule.
Transcription is the process of using the code in a DNA molecule to make an RNA molecule; translation is a process of using the code in an RNA molecule to make a protein molecule.