I love to draw but I am not good at it. My visual art skills are totally in appreciation versus execution
Is all drawing the same, or are there different types? 
There is art drawing and technical drawing 
what is the difference?
Technical drawing
Technical drawing, drafting or drawing, is the act and discipline of composing drawings that visually communicate how something functions or is constructed.
Technical drawing is essential for communicating ideas in industry and engineering.
To make the drawings easier to understand, people use familiar symbols, perspectives, units of measurement, notation systems, visual styles, and page layout. Together, such conventions constitute a visual language and help to ensure that the drawing is unambiguous and relatively easy to understand. Many of the symbols and principles
and art critic John Ruskin emphasised the importance of perception in the drawing process in his book "The Elements of Drawing". He stated that "For I am nearly convinced, that once we see keenly enough, there is very little difficult in drawing what we see".
- Visual memory
This has also been shown to influence one's ability to create visually accurate drawings.
Short-term memory plays an important part in drawing as one's gaze shifts between the object they are drawing and the drawing itself