A sketch is a drawing, generally out of pencil, chalk, pastels, crayons, etc., generally wth only one color. A portrait can range from a painting to a drawing or photograph, generally multicolored.
An isometric is more specific
The main difference is the means by which each is accomplished. A traditional illustration is a sketch, painting, drawing, etc. A photo illustration is just that - a photo.
A technical drawing is drawn precisely to a scale. Measurements taken from the drawing can be scaled up to produce or build a full size structure or machine, etc. A freehand drawing could be a simple sketch, detailed drawing, rough doodle, of a subject and is classed as a picture.
An isometric is more specific
Sketching is a quick drawing done to put your ideas down, it's often lineart and very messy but captures the general idea. Rendering is the process of refining and adding shape and form to a drawing/painting in the terms of shadows. Ie a slightly more refined process.
Sketch
For a photograph you need a camera for a sketch you need a pad and pencil
Artists use charcoal for drawing. The drawing is a charcoal drawing or sketch.
Cause if your gonna plan its in your head and if your gonna sketch you have to write it or draw it first
when you sketch you proportion a picture of something and a sketch is always black and white. When you draw you create a picture of something without proportioning it and you usually color it . When you construct a geometric figure you use straight lines to form a closed figure :)
A sketch is a drawing, particularly a quick drawing that is not completely detailed. A plan can be a drawing of a building's design, showing where the rooms are, the halls are, the doors are, and so forth. So a sketch could be of a plan, but plans can be other things as well. The most common use of the word plan is to mean a sequence of actions that one has decided upon, such as, first I will have dinner, then I go for a walk, then I will watch television, then I will go to bed. That would be a fairly simple and mundane plan, but still a plan.