ENCs (Electronic Nautical Charts)
are a type of nautical charts that are designed for display on a personal computer screen. Accordingly, they appeared much later than paper maps. There are several varieties of ENC. One of them is a raster map. This is a scanned, digitized paper map. Now they are almost never used. Instead of them, vector maps of S -57 standards, etc. are used. Their difference from raster maps is that all objects on them - land, dangerous and non-dangerous objects, the sea - they are all selected as separate objects of the world.