The distributed network, as the term is used in crypto, is covered in the entry Decentralization, which explains how control and data are spread across many participants and what that means for security and governance. This page gives a short definition and explains how the names relate.
A distributed network is a set of computers, or nodes, that share data and work among themselves without depending on one central hub. Each node connects to several others, so information can travel by many routes and the network keeps running if individual machines go offline. Public blockchains are distributed networks in which every full node holds a copy of the ledger, an arrangement described under distributed ledger technology. The structure is usually built from peer-to-peer connections.
Engineers draw a distinction that everyday crypto writing often blurs. "Distributed" describes where data and computing sit: on many machines. "Decentralized" describes who controls them: many independent parties. A big company can run a distributed network entirely on its own servers, which is distributed but not decentralized. Public blockchains aim to be both, which is why the terms are often used interchangeably. The closely related entry decentralized network covers network design in more detail.