In Toronto, the difference between a condo and an apartment comes down to ownership. A condo is a home you buy and hold title to, governed by a condo corporation, while an apartment is a unit you rent from a landlord who owns the whole building.
The word apartment really describes a layout, a self-contained residence sitting inside a larger building. A condo and a rental apartment can look identical from the hallway. What separates them is who holds the deed and what you are allowed to do with the space. Buy a condo and you own your unit outright, along with a share of the hallways, elevators, lobby, and amenities. Those shared spaces are the common elements, and your stake in them is tied to your unit.
Condominiums in Ontario are created and governed under the Condominium Act, 1998, and the sector is overseen by the Condominium Authority of Ontario. A volunteer board of directors runs each corporation, approves the budget, and collects monthly maintenance fees that cover building upkeep, insurance on the structure, and the reserve fund. On top of that you pay property tax and your own mortgage. You can renovate inside your walls. Selling is your call whenever the time feels right. The unit passes to your estate like anything else you own.
A rental apartment runs on a different footing. One owner, often a property company, holds title to the entire building and leases individual units to tenants. That relationship is governed by the Residential Tenancies Act, 2006, and disputes go to the Landlord and Tenant Board rather than a condo board. Rent replaces a mortgage, so no equity accumulates for you. Decisions about pets, paint colour, or subletting sit with the landlord. Purpose-built rental buildings in Toronto are apartments in this sense from the day they open their doors.
One detail trips people up. An individual condo can be rented out by whoever owns it, so a tower full of condos might function mostly as rentals. The unit is still legally a condo, and buying it depends on the owner choosing to sell. That overlap is where the question of renting versus owning gets real, and it is worth reading whether it is better to rent or buy in Toronto before you decide.
Related reading: Is It Better to Rent or Buy in Toronto?, Condo Maintenance Fees in Toronto, and What Are Common Elements in a Toronto Condo?.