Hi Techie711,
Thank you for asking. If your income is higher and usually end up owing tax when you file your tax, claiming "0" will increase more tax withholding and you may want to consider add an extra amount on line 4(c) if you would like to have more withheld. If your income is lower and usually end up with refund, claiming "1" will reduce your tax withholding so you can have more take home pay. Our W-4 calculator will be a great tool to assist you on filing your W-4.
https://turbotax.intuit.com/tax-tools/calculators/w4/