Software quality refers to a software's conformance to its stated functionality, performance requirements, and development standards, as well as implicit characteristics expected of professionally developed software. Key quality attributes that measure software quality include correctness in providing specified functionality, reliability in operating dependably, robustness in working under unexpected conditions, usability through a user-friendly interface, and maintainability to allow for post-release modifications. Software quality aims to ensure customer satisfaction by delivering all expected capabilities based on performance, standards, and ease of use.

2. Software Quality
Definition –
Software quality means conformance to explicitly stated
functionality and performance requirements, explicitly documented
development standards, implicit characteristics, expected for
professionally developed software.
Your requirement – you want a robust software.
standards – rule or technique you have to follow
implicit characteristics – feature is not defined but should be there
in a software.
Or Software quality is defined as the quality that ensures customer
satisfaction by offering all the customer deliverable based on
performance, standards and ease of operation.

3. Quality Attributes
Some of the major quality factor used to measure the quality of software are:
1) Correctness -> Provide Functionality as specified in requirmnt specification.
2) Reliability -> Software is reliable if user can depend on it.
3) Robustness -> Product can work in unexpected circumstances.
4) Performance -> Product provide result as expected by usr.
5) Usability -> Provide user friendly interface that is easy to use.
6) Verifiability -> Properties can be verified easily.
7) Maintainability -> Modification can be done after initial release.
8) Portability -> Product can run on different environment.
9) Productivity -> Quality of S/W process, how faster product can be
delivered.
10) Timeliness -> Process Related Quality, Ability to deliver a product on
time.