I've seen some people using the terms dfa…

I've seen some people using the terms dfab and dmab lately – what do they mean? The context implies the same as amab and afab, are either better to use and is there a d8stinvtion between the two sets?

dmab and dfab mean designated male or female at birth. so yes they mean the same thing as amab and afab. it doesn’t matter which one you use. they’re both alternatives to mtf and ftm. 

mtf and ftm are valid if that’s how someone wants to describe their own gender or experience but afab/amab and dmab/dfab are better when talking about trans and nonbinary people in general.