My meter and lab report showed different numbers

I recently checked my glucose with my home meter and later had a laboratory test, but the numbers were not the same.

I expected them to match exactly, so I was unsure whether my meter was inaccurate or whether some difference is normal between home testing and laboratory measurements.

For people who have compared both, what can cause these differences? How do you know when a variation is expected versus when you should check the meter or discuss it with your healthcare team?