The term blockchain scalability refers to the capability of a blockchain network to handle an increasing amount of transactions efficiently without compromising performance. Scalability has become a critical issue as cryptocurrencies like Bitcoin and Ethereum face challenges with transaction speed and fees due to network congestion. Solutions to enhance scalability include layer 2 protocols, such as Lightning Network and sidechains, which aim to process transactions off the main blockchain while maintaining security. Ensuring scalability is essential for widespread adoption and usability of blockchain technologies.