Adobe Illustrator is a vector graphics editor developed and marketed by Adobe Systems. wikipedia.org

Adobe Photoshop is a graphics editing program developed and published by Adobe Systems Incorporated. wikipedia.org

A sketch is a rapidly executed freehand drawing that is not usually intended as a finished work. A sketch may serve a number of purposes: it can be used to record something that the artist sees, develop an idea for later use or as a quick way of graphically demonstrating an image, idea or principal. wikipedia.org

Realist painters render everyday characters, situations, dilemmas, and objects, all in a "true-to-life" manner. Realists tend to discard theatrical drama, lofty subjects and classical forms of art in favor of commonplace themes.

Portrait painting is a genre in painting, where the intent is to depict the visual appearance of the subject. Beside human beings, animals, pets and even inanimate objects can be chosen as the subject for a portrait. wikipedia.org

Oil painting is the process of painting with pigments that are bound with a medium of drying oil. wikipedia.org

Drawing is a form of visual art that makes use of any number of drawing instruments to mark a two-dimensional medium. Instruments used include graphite pencils, pen and ink, inked brushes, wax color pencils, crayons, charcoal, chalk, pastels, various kinds of erasers, markers, styluses, and various metals. wikipedia.org

Acrylic painters modify the appearance, hardness, flexibility, texture, and other characteristics of the paint surface using acrylic media or by simply adding water. Watercolor and oil painters also use various media, but the range of acrylic media is much greater. wikipedia.org