QPlainTextEdit is class in QtGui module which provides a widget that is used to edit and display plain text.
QTextEdit is a class from the Qt Toolkit which provides a widget that is used to edit and display both plain and rich text
"If you want to display your file as plain text the widget qplaintextedit is better then qtextedit"
from question "How to use Qt read file and display quickly?"
"I have tried connecting the qscrollbars but the maximum of the qplaintextedit is smaller than the qtextedit s"
from question "Pyside scroll two qtextedits simultaneously"