directly makes possible the quantitative treatment of the digitally acquired ESEM images, and allows image recognition and image processing by machine learning based on neural network. Applications Some representative applications of ESEM are in the following areas: Biology An early application involved the examination of fresh and living plant material including a study of Leptospermum flavescens. The advantages of ESEM in studies of microorganisms and a comparison of preparation techniques have been demonstrated. Medicine and medical The influence of drugs on cancer cells has been studied with liquid-phase ESEM-STEM. Archaeology In conservation science, it is often necessary to preserve the specimens intact or in their natural state. Industry ESEM studies have been performed on fibers in the wool industry with and without particular chemical and mechanical treatments. In cement industry, it is important to examine various processes in situ in the wet and dry state. In situ studies Studies in situ can be performed with the aid of various ancillary devices. These have involved hot stages to observe processes at elevated temperatures, microinjectors of liquids and specimen extension or deformation devices. General materials science Biofilms can be studied without the artifacts introduced during SEM preparation, as well as dentin and detergents have been investigated since the early years of ESEM. Commercial ESEM The ESEM has appeared under different manufacturing brand names. The term ESEM is a generic name first publicly introduced in 1980 and afterwards unceasingly used in all publications by Danilatos and almost all users of all ESEM type instruments. The ELECTROSCAN ESEM trademark was obtained intermittently until 1999, when it was allowed to lapse. The word “environmental” was originally introduced in continuation to the prior (historical) use of “environmental” cells in transmission microscopy, although the word “atmospheric” has also been used to refer to an ESEM at one atmosphere pressure (ASEM) but not with any commercial instruments. Other competing manufacturers have used the terms "Natural SEM" (Hitachi), “Wet-SEM” (ISI), “Bio-SEM” (short-lived, AMRAY), “VP-SEM” (variable-pressure SEM; LEO/Zeiss-SMT), “LVSEM” (low-vacuum SEM, often also denoting low-voltage SEM; JEOL), all of which seem to be transient in time according to prevailing manufacturing schedules. Until recently, all these names referred to instruments operating up to about 100 Pa and with BSE detectors only. Lately, the Zeiss-SMT VP-SEM has been extended to higher pressure together with a gaseous ionization or gaseous scintillation as the SE mechanism for image formation. Therefore, it is improper to