Grammar help?

[Misakachi]

Since I'm still new to Russian, why is it "воду"?
What is the grammar at work here?

[Raizindabern]

Accusative case. All nouns that end with «А» or «Я» have their endings changed for «У» and «Ю» respectively, this indicates us that the noun is in a Direct Object form and thus is the entity the action acts upon.

For a far more detailed explanation, click here.

[Misakachi]

Спасибо! )