i have two worksheets in one document

i need to have cells from one worksheet populate with text data from specific cells in the second sheet

example being

sheet one has a 2 columns - Code and code description

sheet 2 has code and code description but the descriptions are missing

i need the missing desciptions in sheet 2 to be populated from sheet one and i also need them to populate to match the individual codes, so all code 10.6.12 in the entire document get the same description, all code 14.3 across the doc get the same description etc..

can anyone tel me how? can it be done to begin with?