pH buffered

[StrangGuy]

Hi,
I am using Liquid Earth (LE) as my nutrient solution. My question though may be a general one in regards to the term “pH buffered”.

LE has the following benefit statement.
• pH buffered, immediately available to plants. Liquid Earth's liquid formulas are easy to use, blend readily with water and are pH buffered so they're immediately available to plants for a longer period of time.

From instructions when mixing the LE with water it wants the water to be balanced to a pH of 7.0 prior. It is also my understanding that most plants like PH somewhere in the range of 5.5-6.5.

1. What does this “pH buffered” really mean?
2. Does pH even matter if a product claims to be “pH buffered”?
3. If it is “pH buffered” why wouldn’t a pH of 8.5 be sufficient prior to adding solution?

Sorry for the question list, someone may be able to answer them all in one statement, but this is what I need to learn.

Thanks,
StrangGuy