Question

What does scalability and robust mean?

Answer 1

Scalability - Means software can accommodate a larger user base as it grows.
Robust - Means the code is well constructed and software is secure

Answer 2

scalability means that your application being able to handle more users/datas at the same time. Robustness in application means your application being able to handle errors or unexpected/incorrect inputs. Also, means steady, strong, and healthy code.

Answer 3

Scalability: will the software still perform correctly and efficiently when the problems grow in size
Robust: will the software deal with unusual situation gracefully and avoid crashing?

You can read more here: https://moodle.augustana.edu/pluginfile.php/405462/mod_resource/content/0/Skrien - Elegant Software Criteria.pdf