The "Attacks" Stat in the statline is number of attacks without accounting for any equipment. For example, one might imagine a model with an A of 2. This model, with no wargear, gets 2 attacks.
Some wargear increases your number of attacks. So imagining again a model with an A of 2, but who was also wielding a weapon that said "when the bearer fights, it makes an additional attack" will get to make an extra attack in the fight phase. So, this model would make 2+1 = 3 attacks in the fight phase.
If you REPLACED that piece of wargear with another piece of wargear that did NOT have that language, it would no longer gain a bonus attack. So, it would only have 2 attacks in the fight phase.