With the entry into force of Markets in Crypto-Assets Regulation (MiCA or MiCAR), there are many questions regarding the complex case-by-case analysis of the legal framework of crypto-assets that fall within its scope. This article aims to contribute to the study and understanding of the legal definition of distributed ledger technology (DLT). To this end, a critical-descriptive analysis structured into two chapters is carried out. The first explores the concept of blockchain, namely the phenomenon of decentralization, blockchain technology and cryptocurrencies, its disruptive potential, functions and main characteristics. This chapter serves to contribute to the understanding of the issues raised in the second and last chapter, which in turn focuses on the exclusion of the concept of blockchain from the legal definition of DLT under MiCAR. For this purpose, in addition to the brief critical-descriptive analysis of the legal definition of DLT, a critical analysis of the distinction between blockchain technology and distributed ledger technology is included.