I'm looking into gaming laptops and when I look at reviews for ones I'm interested in assuming they list the model number I often find the last 2-3 characters are different. It's also common on online stores to have slightly different model numbers. For example: Acer Predator Helios 300 PH315-51-785A on Micro Center and Acer Predator Helios 300 Gaming Laptop PH315-51-78NP on Amazon, and countless examples of just saying Acer Predator Helios 300 and giving the release year. It's all so confusing. Are there any portions of the string i can ignore. As far as I can tell the PH315 is important. I also noticed the 785A had a 512 gb ssd while the 78 np had a 218 gb ssd.
Yes, the PH315-51-78 is the "main" model number. The "5" stands for 512GB of memory (otherwise, it carries 256GB of memory). The letters after that stand for the types of wireless interfaces supported. For example, the "A" stands for "All", which are a,b,g,n,ac. The "NP" means only the ac internet is available. Other than that, there is no difference between them.