A TextBlock control is a fixed-height rectangular box that stays the same, no matter the state of other controls. TextBlock controls can extend to several lines. Users don’t interact with TextBlock controls.
Use TextBlock controls to label a group of related controls, or to display instructive text near a group of related controls. Related controls typically appear below the TextBox control in the same view.
A TextBlock control doesn’t include actionable controls.
One of the strengths of a Windows Phone device is displaying info in clear, beautiful typography. Take advantage of this design characteristic when you advise users on the use of a TextBlock control: use succinct and clearly legible words or labels.