We are hearing and reading a lot of terms for placing and finishing concrete. We do not understand some of these terms. See the list attached and please enlighten us as to the meaning of the "terms."
You are not alone in having asked this question. I will try to answer your question and I will organize the terms you sent me in alphabetical order:
Darby: A hand manipulated straight edge of about 3' to 8' long. Darby tools are used in the early stages of the fresh concrete leveling operation. They may have received their name from the plaster trades. Darbys are used preceding supplemental floating and finishing.
Edger: A finishing tool used on the edges or perimeters of fresh concrete to provide a rounded corner or edge.
Float: A tool (not a darby), usually made from wood. Used in the finishing or smoothing operations to impart or deliver an even but still open texture to an unformed or flat surface of fresh concrete.
Screed: A tool for stringing off concrete surface, sometimes referred to as a "strikeoff." A screed can be as simple as a long two by four, or as complicated as a mounted machine with wheels on a form track or tractor treads of its own.
Trowel: A flat broad blade steel hand tool used in the final stages of finishing operations to impart a relatively smooth surfaces; also a flat triangle blade tool used for applying mortar masonry.
I can find more definitions for you if need be, please stay in touch.