# Concepts

> How the STX exchange works: binary contracts, order matching, liability, settlement and the limits that apply to your account.

Source: https://docs.stxapp.io/concepts/

STX is an exchange, not a sportsbook. There is no house price to take: every
price on the book was put there by another participant, and you can put your own
there too.

That changes what you need to understand before writing code. These pages cover
the model the API is built on. Read them in order if you are new to the exchange,
or jump to whichever one your current question belongs to.

## Start here

  - [United States and Canada](/concepts/us-and-canada/): Two exchanges under different regulators. Which one you integrate with changes almost everything, and accounts do not carry across.
  - [How markets work](/concepts/how-markets-work/): Binary contracts that settle at $1 or $0, what a price means, and how to read a market's status.

## Trading

  - [Order types](/concepts/order-types/): Limit and market orders, how each fills, and what happens to the quantity that does not.
  - [Positions and liability](/concepts/positions/): Order liability, position liability, and why filling an order can increase your available balance.
  - [Settlements and payouts](/concepts/settlements/): When a settlement is created, the fields it carries, and how profit and loss is computed.
  - [Market symbols](/concepts/market-symbols/): How to read a symbol, and how to map STX markets onto a universe you already track without a lookup.
  - [Market and order status](/concepts/market-status/): The seven market statuses and the nine order statuses, which are terminal, and which transitions are possible.
  - [Combos (preview)](/concepts/combos/): An upcoming feature: one contract across several markets, priced by request for quote. Not available to try yet.

## Constraints on your account

  - [Account limits](/concepts/account-limits/): Ceilings on order liability and exposure. They surface as a rejected order rather than an error about limits.
  - [Rate limits](/concepts/rate-limits/): What is enforced today, and how to build so that future limits are a non-event.

Once the model makes sense, [Quick Start](/quick-start/) takes you from creating
an API key to a resting order and a live feed of your own fills.