Yeah most likely he's referring to building placement. Holding down shift to make multiple buildings is a must in DM, in RM I think it's good to learn as well but in general I think just knowing your hotkeys is more important. For the original game there's a page in the Academy, for DE check your settings and edit them to your liking there. With DE you also get a bunch of things like the "Select All Building X" Hotkey which I find makes cycling redundant most of the time.
But yeah, hotkeys are definitely the number one thing when it comes to speed. A few good ones to get down at the start are:
- Select TC and queue villagers
- Build a house
- Select whatever is your backbone militare building and queue a unit (e.g. Archery Range - CA)
Once you start getting into it you'll probably be adding more and more to your register as you become more experienced.
And although we aren't as hardcore with learning "build orders" as the Age2 people, knowing a few basics like how much eco is resonable to have when aging up is good. Someone showed me this really professional
Youtube channel and I've been recommending it ever since, check out his Tool Rush builds and Conti start, or just look at whatever interests you. 
//The warrior of Isola
"I lack quotes that demonstrate Humor Intelligence or anything about me."
Pineapplefish
Cleidopus gloriamaris