Which button is used to enlarge or minimize the information displayed on the screen?

For increasing font size of text and make everything bigger in the web browser you can usually use CTRL and the +/- key(hold the CTRL key as you tap the + or - sign to increase or decrease the size) or if u have a mouse with wheel you can just hold the CTRL key down and increase/decrease with the wheel

if you mean to MAXIMIZE and minimize a window/program then you can in most cases hold the Windows key and press up/down/left/right to maximize,minimize, moving it left or right respectively...

bonus tip: if you got multiple monitors connected to you pc then you can do the same as mention above except for also holding the "shift" key to move a window/program between monitors without changing the size of it...