Sylvari - Talking Tree People

Sylvari, children of the Pale Tree, with the knowledge of Ventari's Tablet, which were the basic guildlines to life for the Sylvari. The Pale Tree was a seed planted by a human named Ronan and raised by a centaur named Ventari over 250 years before the events of Guild Wars 2. The home of the Sylvari is The Grove, located in western Maguuma, under Kryta and next to the Maguuma Waste.

Ventari's Tablet states that:
I. Live life well and fully, and waste nothing.
II. Do not fear difficulty. Hard ground makes stronger roots.
III. The only lasting peace is the peace within your own soul.
IV. All things have a right to grow. The blossom is brother to the weed.
V. Never leave a wrong to ripen into evil or sorrow.
VI. Act with wisdom, but act.
VII. From the smallest blade of grass to the highest mountain, where life goes--so, too, should you.

Though the Sylvari does not have a government, they are guided by the Pale Tree and the Dream. The Dream connects the Sylvari to the Pale Tree,and to other Sylvari born from the Pale Tree, not physically but mentally. The Dream is also what drives the Sylvari to do what they want to do, based on their experience in the Dream. The Pale Tree guides the Sylvari to achieve their Dream, though the Dream is interpreted by the Sylvari themselves.

Though all Sylvari from the Pale Tree have the Dream, not all of them believes in it. The Soundless are Sylvari that cut themselves from the Dream. Just as there is hope and faith in the Dream, there is a counterpart called the Nightmare. The Nightmare Court is consist of Sylvari that believe in the Nightmare. Similar to the Charr, where the Flame Legion is fighting with the other three legions, the conflicts between the Nightmare Court and the Sylvari who belives in the Dream rages on.

Info from Guild Wars 2 Wiki

Best conversation between NPCs in The Grove: source
Sylvari: "Your golem is strange. Was strange, rather."
Asura: "You drove it away, you know that? I've never seen a golem run that fast."
Sylvari: "I just wanted to ask it a few questions."
Asura: "Yeah, I know. You guys are full of them."
Sylvari: "Oh yes, what it's like to be a golem? Does it dream? Does it have a family?"
Asura: "That was the last straw you know.After that question about turtles in the desert, you asked it about its mother."
Sylvari: "So?"
Asura: "It doesn't have a mother. It's a golem. You crossed its circuits. I don't know how you did it, but you weirded out MY golem!"
Sylvari: "So, you are the mother? Or the father?"
Asura: "What? Well, I-I guess I...Oh no, you're not getting in my head. You just stand there and help me monitor the gate."
Asura: "Am I the mother? Blazing braces, this is what I get for working with the tree children."