No Man's Sky/Anomaly

The Anomaly is a massive space station that is unlocked near the start of the game. Just continue following the main quests.

When unlocked, it can be summoned at any time, in any system, except on planets or during combat, by opening the quick menu (down arrow key on console) and select "summon space anomaly".

What you can do
The Anomaly allows you to spend salvaged data and nanites to get upgrades, base parts, and exocraft blueprints. You can also redeem quicksilver for rewards, ranging from fireworks and jetpack trails (cosmetics) to new items, mostly decorative.

You can also find an egg sequencer, allowing you to genetically modify eggs, and the creature inside them, with elements. Note that overdoses can have drastic, unexpected results.

Finally, the Nexus allows you to accept quests for quicksilver. To find the mission board at the spherical thing near the landing pads. Note that it is currently disabled on Nintendo Switch.