Front-ends are graphical user interfaces (GUI, i.e., a website or application) that facilitate communication between the user and a DeFi protocol over the internet. Essentially, a front end displays blockchain data in human-readable format, making it easier for users to communicate their transactions to the blockchain.
When initiating a transaction, a sender specifies the recipient’s blockchain address, the amount to be sent, and uses the sender’s private key to sign the transaction, ensuring its security and authenticity. As the transaction is validated, the amount of digital assets associated with a given public address is updated.
For clarification, a front-end is not an intermediary. A front end is more like a “translator” from humans to blockchains, similar to the way email works. When sending an email, a person writes the email using the Roman alphabet to coherently write words and sentences. When that email is sent, the email protocol “translates” the message into a form that can be transmitted to the recipient in data packets that can be sent over the internet. Likewise, front-ends “translate” human-understandable activities into a data form that blockchains can understand.