The interface of Inkscape is user friendly specially for newbie. List of button at vertical left toolbar are quick easy navigation. Its symbol represent its function. There’s Shape Tools 
including square, 3D box, circle, star, swirl. This tools easy to use to create a shape. To scale or select we can use this Select Tools 
. Beside using Shape Tools, we also can use these calligraphy pen, path , and pencil to create freehand image 
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Inkscape Interface
What is Vector Graphic?
Inkscape is vector graphic editor. File extension of Inkscape file is SVG or Scalable Vector Graphic. What is a vector and why it is scalable? You may have no idea what it is, but you can see this illustration for an example. Vector image based on geometric while bitmap graphic based on pixel. Main benefit is, vector graphic is scalable without reducing its quality.
Compare to bitmap graphic, if you scale it to larger or smaller size, the result is annoying image because you scale pixel not image. You can expand or shrink from original size without losing any of thefidelity of the original image. If you still want to have a bitmap image when you’re done, it’s easy to convert an SVG image to a bitmap. This is called rasterization. Just export SVG image to .png or .jpg file. Although it is easy to go from vector to bitmap, it’s not easy to go from bitmap to vector.
Inkscape:Introduction
Quoted from official Inkscape site “An Open Source vector graphics editor, with capabilities similar to Illustrator, CorelDraw, or Xara X, using the W3C standard Scalable Vector Graphics (SVG) file format.
Inkscape supports many advanced SVG features (markers, clones, alpha blending, etc.) and great care is taken in designing a streamlined interface. It is very easy to edit nodes, perform complex path operations, trace bitmaps and much more. We also aim to maintain a thriving user and developer community by using open, community-oriented development. “