Dynamic input in AutoCAD can help you when you are working with AutoCAD.
You will learn learn what is Dynamic Input and how to turn it on.
What is Dynamic Input?Well,it is a feature similar to command line which tells you what to do next when you activate your command (example:LINE),it shows you the coordinates,it asks you to specify your first point and so on...just like on the command line.
Blue rectangle: Command line
Red line: Dynamic Input
When you want to lets say draw a circle press down arrow on your keyboard and it will show you the options for that command,if there are options of course.
How to turn on Dynamic Input and where you can find an icon?
It is at the bottom of your screen with the rest of the features (Polar tracking,Ortho...)
Just click on it when you want to turn it on or off.You can press F12 to turn it on too,if that is easier for you.My Dynamic Input is turned OFF as you can see.
If you can not find your icon of Dynamic Input at your status bar with all the ortho and polar features then you need to turn it on at your Aplication Status Bar Menu which is located at the bottom right corner (Down arrow).
You will find there "Status Toggles" and there you can turn on or off all of your status bar features.
This may be a little bit different if you are using a newer version of AutoCAD but that is how this goes.
So, using Dynamic input can be easier to some people,I use it always,it is always turned ON because it is easier to me to have the information of what I am doing next to my cursor than using command line. As I said It is easier for me and it could be or could not be easier for you,but still,not necessary to work with it,you will draw a bolt with and without Dynamic Input.