I have 2 questions maybe somebody can help me with?

is there a difference between using instances and array? Does one help with big scenes and saving memory? I am starting to learn about data blocks to maybe help with this.
I am looking up tutorials but one doesn’t have any volume on this certain situation. the rest is just about instances.

the last question is… the widget.
sometimes I am not able to see or move the mesh with my mouse and I have to use the G key and whatever axes key. Z,Y,X
This doesn’t happen all the time but this has been happening a lot lately and never had this issue before. I have been using ctrl A to reset scale and rotation then reset orgin and had the mesh snap back the orgin but i cant find my widget and only option is to use the G key like i said before.

I checked to see if the widget manipulator is turned off down in the panel or have th object locked somehow in my scale, rotation and location panel. and there fine. any reasons for this?

thanks for the time and advice. I really appreciate it. Starting to understand a lot about modeling but now modifiers, textures, lighting, and compositing next. Lol well at least I am doing good with topology.

thanks again for your time

By widget I assume you mean the 3D manipulator and it sounds like you have deactivated it (
). Click on the manipulator icon to activate it. It is not clear why it “doesn’t happen all the time.” Have you saved a startup file with it deactivated?

Regarding the G key and mouse moves, have you somehow changed the mouse from right-button to left-button? Check the User Preferences Input panel.