Improving blockchain scalability is a pressing issue due to increasing demand, leading to network overload and higher user fees, which subsequently hinder widespread adoption. To address this challenge, several strategies have been suggested as solutions to the scalability trilemma, involving enhancements to the foundational layer, such as sharding, and the utilization of off-chain techniques such as sidechains, state channels, and rollups. The scalability trilemma arises from the inherent trade-offs faced by Layer 1 blockchains, necessitating a delicate balance between decentralization and security. Ethereum, recognizing the limitations in its foundational layer, has strategically adopted a roadmap with a focus on rollups to overcome scalability issues, acknowledging the necessity for enhancements in both data and computational aspects. Blockchain rollups are increasingly seen as a promising answer to the scalability issues encountered by blockchain technology, as they offer a solution that can significantly increase the capacity and speed of existing networks, while also providing a high degree of security and flexibility. This chapter aims to comprehensively explore the complexities of blockchain rollups, examining their characteristics, functions, and their impact on blockchain scalability. Through a detailed analysis, we seek to illuminate how rollups solutions operate and distinguish the features that characterize their contribution to the progression of blockchain technology.