what is the difference between ui-steps-number and p-steps-number in primeng?

Question

I found some code where the steps use ui-steps-number in one module but p-steps-number in another, and I don't know if ui-steps-number was the older version of PrimeNg and the new version now uses p-steps-number or are they different things entirely? documentation only talks about p-steps-number.

<p-steps [model]="items" [readonly]="true">

.p-steps-number {color: red;}

<p-steps [model]="items" [readonly]="true">

.ui-steps-number {color: green;}

https://primeng.org/steps/personal

Answer 1

PrimeNG moved away from the ui-* prefix for CSS classes around version 10, opting to use the p-* prefix instead.

https://github.com/primefaces/primeng/wiki/PrimeOne-Migration