The Solana Wallet Adapter is an open-source library that provides a unified interface for Solana dApps to connect with multiple wallet providers. Instead of building custom integrations for Phantom, Solflare, Backpack, and every other wallet, developers implement the wallet adapter once and gain compatibility with all supported wallets.

From the user's perspective, the wallet adapter powers the 'Connect Wallet' button in Solana dApps — providing a selection modal where users choose their preferred wallet. All major Solana wallets support the wallet adapter standard.

The wallet adapter handles wallet connection, disconnection, transaction signing, and public key retrieval in a standardised way, making it the foundation of Solana dApp development.