Highlight Duplicates In Google Sheets (Row or Column) Using Conditional Formatting

Great! 100% perfect. Thank you so much.

How to highlight duplicates side by side in a row, and apply that formula to all rows??????

this video really helped, thanks

Hello, I have problem with my formula which is "=COUNTIF(ARRAYFORMULA($B$2:$B$2572&$C$2:$C$2572&$D$2:$D$2572),B2&C2&D2"
The formula says "ERROR", everything seems okay but B2 at the end wont link with the b2 column, i mean everything other is highlighted when i click on it but only the last one "B2" is not highlighted when I click, so I think there is the problem. but why? Everything other seems okay, I checked everything 5 times to make sure every , ( ) & is here. Thanks!

Great tips Chester. Thanks!!