Short answer
- An operator of a certified airport is required to conduct airport operations according to an Airport Operations Manual.
- This manual must enumerate the facilities offered by the airport.
- An important aspect of the manual is to describe how airport safety and emergencies are managed, and by whom. Note that the obligations for safety are not specific to airports, but apply to any aerodrome. what is required for an airport is to write in the AOM how they are implemented.
So the difference between an aerodrome and an airport is not about the facilities or the equipment, it's about how it is operated and who checks it is done as intended.
Indeed some equipments are required at an airport (e.g. markings, lights and signs) but they are not specific to airports, they apply to all aerodromes.
Layman language
Aerodrome usually refers to the possibility for aircrafts to land and take-off. This is the point of view of a pilot with needs to takeoff and land. The word aerodrome is derived from the Greek words aeras (αέρας), "air" and dromos (δρόμος), "road" or "course", literally meaning "air course" (Wikipedia).
Airport usually refers to an aerodrome with passengers or freight facilities. This is the angle of view of an airline conducting business. In Canada there are obligations associated with running an airport.
International airport usually refers to an airport with customs and immigration services.
Aeronautical language
For the aeronautical information, a Canadian airport remains an aerodrome. E.g. a list of aerodromes.
Canadian authorities language
In Canada, an airline making business with air transportation must operate at aerodromes holding an airport certificate, aerodromes referred to by the Canadian authorities as airports.
From Canadian Aviation Regulations “airport” means:
an aerodrome in respect of which an airport certificate issued under
Subpart 2 of Part III is in force.
Issuance of the certificate is described at section 302.03, and obligations for the airport operator are described at section 302.07. This is a very long list of obligations. An Airport Operations Manual is required, and described at section 302.08.
Summary of section 302.07 - The operator of an airport shall...
Summary of section 302.08 - The Airport Operations Manual must contain...
... all the informations necessary for the authorities to verify that
the airport meets the applicable standards...
- Physical characteristics
- Obstacle limitation surfaces
- Declared distances
- Lighting, markers, markings, signs
- Access to the movement area and control procedures...
- Enumeration of the facilities and services provided [...] including air traffic services and aeronautical information and communication
services, navigation aids, and aviation weather services
- Emergency response measures
- Airport safety measures
- Safety management system required under section 107.02
- Description of the safety management system's components specified in section 302.502
The operator of an airport shall operate the airport in accordance
with the Airport Operations Manual.
ICAO publishes a set of standards and recommended practices (SARPs), including Annex 14 — Aerodromes, Volume I — Aerodrome Design and Operations. Standards are fully enforced by ICAO members, recommended practices are encouraged but still optional for members.
Summary
In Canada, airlines are required to conduct business according to specific rules regarding aircrafts, passengers, security, etc. One of these obligations is to use airports holding a valid certificate.
Airport operators are required to conduct operations according to the practices listed in related publications. They must use an Airport Operations Manual describing how these practices are implemented. The authorities deliver the airport certificate based on this manual, and on-site inspection.
- Airports operators are required to install equipments such markings, but this is valid for any aerodrome.
- Airport operators are not required to offer such services as immigration, ATC, weather station, refueling, gateways, etc, however they are required to publish, in the Airport Operations Manual, which services are available.
It's up to airlines to select and use the appropriate airports, according to their needs and legal obligations.