windows – Action to display the MacBookPro Desktop screen

I need to know how to prevent open windows from disappearing when I work with one or more programs. It seems that they disappear when I stay on the cursor for too long, but I do not understand how to solve this problem in the preferences. For example, I need to keep my browser open for reference while I type something in Pages. Even if I minimize the browser, it will disappear in some cases. Of course, by clicking on the icon in the desktop bar, you will reopen the browser where it was, but the Pages window will disappear, and so on. I need it to stay open simultaneously. What to do? MacBookPro calls Retina, 15 inches, mid-2014 with Mojave 10.14.4. Thank you.