Usually from the seller's side of the transaction — but that is a convention rather than a law, and your agreement should say what happens when it does not apply.
Conventionally in Calgary, the seller agrees compensation with their listing brokerage, and a portion of that is offered to the brokerage representing the buyer. The money comes out of the sale proceeds at closing, which is why buyers often describe the service as "free".
It is more accurate to say it is paid indirectly. It comes from the transaction, which is funded by the price you pay.
Generally no, and this is where buyers most often reason themselves into a bad position.
On a typical resale, the seller has already agreed their brokerage's compensation before you appear. If you arrive unrepresented, that agreement does not usually shrink — the listing side simply retains more of it. You have not saved money; you have declined representation at the same price.
The same logic applies on new construction, where the builder ordinarily pays a buyer's agent from the sale and does not discount the home for turning up alone. The builder registration rule →
The choice is rarely "pay for an agent or save money". It is "have someone on your side, or not, at a similar price".
In Alberta you will sign a written service agreement with a brokerage, and it should be clear about compensation — including the scenario that trips people up: what happens if the compensation offered on a particular property is less than agreed, or none is offered at all.
That situation does occur, and the agreement determines whether any shortfall falls to you. Ask specifically:
A good agent will answer all four without hesitation and put it in writing. Vagueness here is itself informative.
Representation here works through designated agency: the individual REALTOR® you hire represents you, not the brokerage as a whole. That matters when two agents from the same brokerage are on opposite sides of a deal — each represents their own client, with the brokerage managing the arrangement.
It is a different model from the one you may have read about in American coverage, so be careful applying US commentary to an Alberta transaction.