Question
You have heard of smart contracts in cryptocurrency contexts. What is a smart contract?
Answer
It is a automated or self-executing bid to buy or sell cryptocurrency when a condition is met (e.g., a price point is reached). As with stock trading with limit orders based on price, a smart contract is the equivalent with cryptocurrency. Usually the contract will execute exactly with the parameters you set forth or more in your favor (e.g., it can be cheaper when you buy or more expensive when you sell).
Coinbase supports smart contracts.