The VLT consists of a cluster of four large (8 meter diameter) telescopes, and an (Any measuring instrument that uses interference patterns to make accurate measurements of waves) interferometer (VLTI) which will be used to resolve fine features. The interferometer will include a set of 1.8 meter diameter telescopes dedicated to interferometric observations. The 8 meter telescopes have been named after the names of some astronomical objects in the local Mapuche language: Antu (The (A typical star that is the source of light and heat for the planets in the solar system) Sun), Kueyen (The (Any natural satellite of a planet) Moon), Melipal (The (A small conspicuous constellation in the southern hemisphere in the Milky Way near Centaurus) Southern Cross), and Yepun ( (Type genus of the family Veneridae: genus of edible clams with thick oval shells) Venus).

The VLT 8 meter telescopes can be operated in three modes:
- as a set of independent telescopes (this is the primary mode of operation)
- as a single large incoherent instrument, for extra light-gathering capacity (this mode has now been abandoned)
- as a single large coherent interferometric instrument (the VLT Interferometer or VLTI), for extra resolution (this is occasionally used, usually for observations of relatively bright sources)

The principle role of the VLT is to operate as four independent telescopes, and the interferometry (combining light from multiple telescopes) is a minor secondary role.

In 2005, VLT telescopes produced some of the first (The infrared part of the electromagnetic spectrum; electromagnetic wave frequencies below the visible range) infrared images of extrasolar planets GQ Lupi b and 2M1207b.

More information about Paranal Observatory here (link).