Yes, they're (probably)  the same.

A/G usually  means either of A or G have been observed at that position. The convention should be to put the reference allele first, but you can't guarantee that's being followed.

Alternately, if given as the genotpye for a diploid organsim A/G would indicate one of each allele, ie heterozygous.

A>G explicitly states that A is the reference allele, and that the variant G was observed, but this doesn't on its own tell you whether the variant was heterozygous or homozygous.

they have same meaning, i.e A is replaced by G in the polynucleotide sequence