In this paper, we present a technology summary and update on the latest research advances in luminescent solar concentrators (LSCs). LSCs are optoelectronic devices based on a sun irradiation collector made of fluorophores that, after the solar radiation absorption, re-emit visible light propagating via a waveguide towards smaller area photovoltaic (PV) cells, which convert radiant energy into electricity. Here we review their basic principles, their performance analysis, and measurements, the various types of fluorophores so far employed, and the design and architectures proposed. We also include a brief review of the use of the energy transfer process and photonics to reduce their optical losses and improve their photons trapping efficiency. While their main application today is building integrated PV to meet future energy and emission targets, other envisaged alternative applications are also briefly summarised. The final performances in terms of electrical power conversion are linked to various fluorophores and device designs, while current limitations of scalability and stability are impeding their wider use.