What does this following maf column mean?

Question

[Gene_MMP8]

I was trying to query a maf file based on variants when I came across two columns: tumor_seq_allele_1 and tumor_seq_allele_2. Now I found out that these two columns are not identical. Also, I know that alleles are different version of the same gene. So what can I say about the variant?
Eg:

Ref: C
Tumor_seq_allele_1: C
Tumor_seq_allele_2: T
______________________
Ref: G
Tumor_seq_allele_1: G
Tumor_allele_allele_2=A

---

So what can I say about the variant in both cases? That the first case, there are C>T transitions and in the second, G>A transition?

[Ram]

Where did you obtain this file from? I've seen this format in TCGA, but in my dataset all allele_1 alleles were the same as Ref Alleles

[Gene_MMP8]

This is obtained from a pan cancer study path.

[Gene_MMP8]

Can you please clarify what tumor_seq_allele_1/2 really mean?

[Ram]

I'm not really sure. I thought it was just Ref and Alt myself, but I guess I was wrong? Or maybe tumors can have both alleles change at a location, given tumors from one person need not be the same genotype?

[Gene_MMP8]

The maf file documentation doesn't clarify it either.