> ## Documentation Index > Fetch the complete documentation index at: https://docs.polymarket.com/llms.txt > Use this file to discover all available pages before exploring further. # Markets & Events > Understanding the fundamental building blocks of Polymarket Every prediction on Polymarket is structured around two core concepts: **markets** and **events**. Understanding how they relate is essential for building on the platform. ## Markets A **market** is the fundamental tradable unit on Polymarket. Each market represents a single binary question with Yes/No outcomes. Every market has: | Identifier | Description | | ---------------- | ------------------------------------------------------------------------ | | **Condition ID** | Unique identifier for the market's condition in the CTF contracts | | **Question ID** | Hash of the market question used for resolution | | **Token IDs** | ERC1155 token IDs used for trading on the CLOB — one for Yes, one for No | Markets can only be traded via the CLOB if `enableOrderBook` is `true`. Some markets may exist onchain but not be available for order book trading. ### Market Example A simple market might be: > **"Will Bitcoin reach \$150,000 by December 2026?"** This creates two outcome tokens: * **Yes token** - Redeemable for `$1` if Bitcoin reaches `$150k` * **No token** - Redeemable for `$1` if Bitcoin doesn't reach `$100k` ## Events An **event** is a container that groups one or more related markets together. Events provide organizational structure and enable multi-outcome predictions. ### Single-Market Events When an event contains just one market, it creates a simple market pair. The event and market are essentially equivalent. ``` Event: Will Bitcoin reach $100,000 by December 2024? └── Market: Will Bitcoin reach $100,000 by December 2024? (Yes/No) ``` ### Multi-Market Events When an event contains two or more markets, it creates a grouped market pair. This enables mutually exclusive multi-outcome predictions. ``` Event: Who will win the 2024 Presidential Election? ├── Market: Donald Trump? (Yes/No) ├── Market: Joe Biden? (Yes/No) ├── Market: Kamala Harris? (Yes/No) └── Market: Other? (Yes/No) ``` ## Identifying Markets Every market and event has a unique **slug** that appears in the Polymarket URL: ``` https://polymarket.com/event/fed-decision-in-october └── slug: fed-decision-in-october ``` You can use slugs to fetch specific markets or events from the API: ```bash theme={null} # Fetch event by slug curl "https://gamma-api.polymarket.com/events?slug=fed-decision-in-october" ``` ## Sports Markets Specifically for sports markets, outstanding limit orders are **automatically cancelled** once the game begins, clearing the order book at the official start time. However, game start times can shift — if a game starts earlier than scheduled, orders may not be cleared in time. Always monitor your orders closely around game start times. *** ## Next Steps Learn how prices are determined and how the order book works. Start querying markets and events from the API.