The form W-2 taxpayer will receive the beginning of the year to report or declare his taxes and according with his status, depends and credits may receive a favorable tax refund. The taxpayer may receive more than one form depending in how many companies he was employee during that year.
The form W-9 taxpayer may need to fill in case the company or employer will request it, this form is use to collect the personal information of the taxpayer so at the end of the year such company will send the taxpayer a form 1099NEC to report his income tax.