It means angular application can work on any OS platform.
It can be deployed on any server either linux, windows, ubuntu...
Used with any Server side Language:
Angular can be combined with any technology stack.
It can be easily used with any server side languages.
Speed And Performance :
It used Typescript to follow OOPS, which makes application scalable.
Its speed can increased by using AOT, Lazy-loading, Angular SSR.
Unit Testing :
We can Use Karma, Jasmine, Mocha, to write Unit test cases easily.
For code coverage we use Istanbul.
We have to follow OOPS , if we use Typescript.