Test Scenarios provides and overview of what needs to be tested in which conditions.
Test Cases outline how that condition will be tested with positive and negative outcome by changing the pre-conditions and required variables.
Test Cases are most important part of SDLC and without this, it’s tough to track, understand, follow and reason out something, but in Agile Test Cases are being replaced fast with Test Scenarios.
Example: Login Page with username, password, login and cancel buttons
If asked to write Test Cases for the same, we will end up writing more than 50 Test Cases by combining different options and details, but if Test Scenarios to be written, it will be a matter of 10 lines as below:
1. To check Application is Launching
2. To check text contents on login page
3. To check Username field
4. To check Password field
5. To check Login Button and cancel button functionality