Memes

Bro, the left and right are originally French, not American, and they're applied worldwide throughout various systems.

Long story short, in the original National Assembly in 1789, people with similar opinions ended up befriending each-other and sitting nearby during the session, so at one point you had all those who thought the revolution ought to go further (give more rights to more people, decrease the power of the king or outright depose him, etc...) sitting on the left, and all those who thought the revolution had gone to far already and ought to slow down sitting on the right.

Of course, by this metric, the very concept of a republic is far left, but the idea is that no matter what system you're in, once it's established enough, wanting to maintain the status quo is being a centrist, wanting change that puts more power in the hands of common people is left wing, and opposing such changes or wanting to undo them to "restore order", often concentrating power in fewer hands, is right wing.

This "power" I speak of was at the beginning just political power, but through the 19th century, the focus shifted towards economic power. Therefore, since the late 19th century, a right wing policy a policy that favors the rich, and a left wing policy one that places restrictions on the rich and welfare policy for the poor to decrease inequality. This is why liberals were initially left wing, but neoliberalism is now mostly regarded as a wing ideology. These are policies that want a weaker state, but more rights/powers for rich individuals.