Automated Production vs Manual Crafting
If you automate your production lines, products are continually created and accumulate in your storages. However if you make everything manually at the craft bench then nothing else is being done while you are manually making that item.
I also discuss (again) the importance of automation compared to manually crafting at the craft bench.
Reinforced Iron Plate Assembler
Reinforced Iron Plate is used for Mk. 2 Conveyor Belts, Constructors and Assemblers. It's best to automate it as soon as possible so you have a supply always being crafted.
With the introduction of the Assembler a while ago you can now produce several new parts. However this means you need to spend time setting up automation for this process which can seem time consuming when you just want 20 of those parts. Manual Automation shows you how to use storage containers for the inputs and outputs of a machine and hence you can fill those containers with materials and parts will automatically be created, all you need to do is top up the containers occasionally.