  The formation of hadrons is a fundamental process in nature that can be
investigated at particle colliders. As several recent findings demonstrate,
with $\mathrm{e^+e^-}$ collisions as a "vacuum-like" reference at one extreme,
and central nucleus--nucleus as a dense, extended-size system characterized by
flow and local equilibrium at the opposite extreme, different collision systems
offer a lever arm that can be exploited to probe with a range of heavy-flavour
hadron species the onset of various hadronization processes. In this review, we
present an overview of the theoretical and experimental developments. The focus
is on open-heavy-flavour measurements. The comparison with model predictions
and connections among the results in electron-positron, proton--proton,
proton--nucleus, nucleus--nucleus collisions are discussed. After reviewing the
current state, we suggest some prospects and future developments.
