It's overscan of the TV.
There are several ways to fix this. Depending on the manufacturer of the TV, They have their own way of naming schemes.
On your remote, try finding anything that relates to the following:
PC/Computer mode,
"Format" or "View Mode" -> "Dot by Dot" or "1:1 pixel mapping"
Full Screen
Full Pixel
Edge to Edge
Screen Fit
etc.