Differences between NDVI calculated using Band math and the NDVI processor

I’ve recently calculated NDVI for a specific area via SNAP and Sentinel 2 images. I used both ways to do it - Band Maths and NDVI Processor. but the result is quite different. which one is more precise?

Hello @satas12825,
If you save the product with both NDVI bands (calculated with NDVI Op and Band Maths), close it, and reopen it, will the values still be different?