View Data Issue

$a was set with the first view load.  Data passed to any view is cached and is available to any subsequent views that are loaded.

I want to ask a question:

First model loads view with data.

And then model loads another model.

Second model loads previous view again with another data without clear.

What happens at this time?

I'm a person from Turkiye. I don't know English very well and i can't write what i want to say sometimes (as now happenes   ).

If i write something by mistake; please don't distress it and try to understand what i want to write.