Would anybody please do let me know how to create graphic images/ effects as mentioned in below images?
I want to know the
tools/ techniques to create such graphics images for web based usage.
Graphic Design Stack Exchange is a question and answer site for Graphic Design professionals, students, and enthusiasts. It only takes a minute to sign up.Sign up to join this community
You can create these illustrations using almost any graphic software.
Adobe Illustrator and Adobe Photoshop are both paid (subscription based, you can try them for free for a month) and can work with vectors. Illustrator is the preferred choice for creating scalable graphics.
Regarding the techniques to make the drawings, you'd have to draw the shapes yourself and then use a combination of filled backgrounds (for the filled clouds and atom) and strokes (for all the lines).
The result will depend on how much practise you have making illustrations, these are not difficult technically, but still very hard to master.