Which is best to use A-records or CNAME?


my own domain can be attached to my bplaced server by both doamin atachement method A-records and CNAME, but i want which one is the best ? and it’s possible to use the both in the same time ?

And please if CNAME is prefered to use can you explain for me what i must fill in the forms in the image bellow for a good configuration :


Thank you