Appareil photo vs. caméra
While English uses a single word for devices that capture imagery, French makes a strict distinction based on the type of media being captured. You must use an appareil photo for still pictures and a caméra for moving videos.
Appareil photo
This term refers exclusively to a camera used for taking still photographs, freezing a single moment in time.
J'ai acheté un nouvel appareil photo pour capturer les souvenirs de mes vacances.
(I bought a new camera to capture the memories of my vacation.)
Le photographe règle son appareil photo avant le début du mariage.
(The photographer adjusts his camera before the start of the wedding.)
Mon grand-père m'a offert son vieil appareil photo argentique.
(My grandfather gave me his old film camera.)
Cet appareil photo est étanche, tu peux donc l'utiliser sous l'eau.
(This camera is waterproof, so you can use it underwater.)
Il est interdit d'utiliser un appareil photo avec flash dans ce musée.
(It is forbidden to use a camera with a flash in this museum.)
Caméra
This word is used strictly for devices that record moving images, such as video cameras, movie cameras, security cameras, or webcams.
Le réalisateur a demandé de déplacer la caméra pour filmer la scène sous un autre angle.
(The director asked to move the camera to film the scene from another angle.)
Il y a une caméra de surveillance à l'entrée du supermarché.
(There is a security camera at the entrance of the supermarket.)
Veuillez allumer votre caméra pour la réunion en ligne.
(Please turn on your camera for the online meeting.)
La journaliste parlait directement à la caméra pendant le journal télévisé.
(The journalist was speaking directly to the camera during the news broadcast.)
Elle a fixé une petite caméra sur son casque de ski pour enregistrer sa descente.
(She attached a small camera to her ski helmet to record her descent.)
Summary
To choose the correct word, simply think about the final result. If you are taking a still photograph, you need an appareil photo. If you are recording video, a movie, or streaming live footage, you must use a caméra.