For more info please check the components's official demos & documentation
demos & documentation
<mat-progress-bar>is a horizontal progress-bar for
indicating progress and activity.
Determinate: Operations where the percentage of the operation
complete is known should use the determinate indicator.
Operations where the user is asked to wait while something finishes
and it’s not necessary to indicate how long it will take should use
the indeterminate indicator.
Operations where the user wants to indicate some activity or loading
from the server, use the buffer indicator.
For situations where the user wants to indicate pre-loading (until the
loading can actually be made), use the query indicator.