It is important to learn truffle-contract before learning truffle because truffle-contract is tightly integrated into truffle. Truffle tests, code to interact with contracts in truffle, deployment code, and so on are written using truffle-contract.

The truffle-contract API is a JavaScript and Node.js library, which makes it easy to work with ethereum smart contracts. Until now, we have been using web3.js to deploy and call smart contracts functions, which is fine, but truffle-contract aims to make it even easier to work with ethereum smart contracts. Here are some features of truffle-contract that make it a better choice then web3.js in order to work with smart contracts:

• Synchronized transactions for better control flow (that is, transactions won't finish until you're guaranteed they've been mined).
• Promise-based API. No more callback hell. Works well with ES6 and async/await.
• Default values for transactions, such as from address or gas.
• Returning logs, transaction receipt, and transaction hash of every synchronized transaction.

Before we get into truffle-contract, you need to know that it doesn't allow us to sign transactions using accounts stored outside of the ethereum node; that is, it doesn't have anything similar to sendRawTransaction. The truffle-contract API assumes that every user of your DApp has their own ethereum node running and they have their accounts stored in that node. Actually this is how DApps should work because if every DApp's client starts letting users create and manage accounts, then it will be a concern for users to manage so many accounts and painful for developers to develop a wallet manager every time for every client they build. Now, the question is how will clients know where the user has stored the accounts and in what format? So, for portability reasons, it's recommended that you assume that users have their accounts stored in their personal node, and to manage the account, they use something like the ethereum Wallet app. As accounts stored in the Ethereum node are signed by the ethereum node itself, there is no need for sendRawTransaction anymore. Every user needs to have their own node and cannot share a node because when an account is unlocked, it will be open for anyone to use it, which will enable users to steal other's ether and make transactions from others' accounts.

If your applications require the functionality of creating and signing raw transactions, then you can use truffle-contract just to develop and test smart contracts, and in your application, you can interact with contracts just like we were doing earlier.