Forms of Art
There are only a few primary forms of art, and these are ancient. In no particular order, they include literature, the visual arts (painting and sculpture) and music. Each form re-creates reality in a different way, and so has its own peculiar strengths and limitations. The kind of world it can convey is dependent on its means.
Literature re-creates reality through the use of concepts. It uses words to describe and show a view of the world. In story form, it uses characters and plot to show a world. In poetry, it uses style and imagery. Because it uses concepts to portray the re-creation of reality, it has a harder time dealing with very visual themes. While it can describe higher level concepts in many ways and provide context for them, it doesn't have the ability to simply point at reality. In other words, the form of the art has strengths and weaknesses.
The visual arts can literally show us a view of the world. Sculpture deals with three-dimensional forms, with the best examples being the human form. They portray the visual equivalent of a concept. A sculpture might show beauty, or grace, or innocence, playfulness, etc. It is able to capture body language and integrate it with pose and form. While other subjects of sculpture are possible, the human form is able to convey metaphysical value-judgments about human life in the world.
Paintings also deal with a visual representation of the world. Their range of subjects is much wider. They can portray situations, events, and the world itself. They're able to convey the full range of metaphysical value-judgments, including the views of the world itself.
The visual arts are slices in time, so they can have difficulty in conveying action, or plots, or motivations, or anything else where time can better express something. Literature is better equipped to deal with those kind of abstractions. It's not impossible for the visual arts to deal with them, but it makes it more difficult.
Music is a very complicated form of art to discuss. While Rand had some thoughts on the topic, she wasn't definitive. Music uses sound in order to convey abstractions. The sound can mirror how the human voice conveys emotions, or how the human body moves in certain moods. It can be fast paced and carefree, or drooping and halting. By relating these sounds to our own experiences with people, the art can convey emotions.
Since it uses sound as its means of communication, it has difficulty conveying specific ideas. It's more of patterns and actions and relationships. It does have an element of time, so is able to communicate change, but it remains fairly abstract.
While these are the basic forms of art, there are many others. Some are variations or combinations of these. A movie might combine music, literature (characters and plot), and visual arts. But the movie is primarily a derivative of literature, and the other elements are added to enhance it, but aren't primary.
Photography may be of the same class as painting, in the visual arts. There's always some debate over whether photography counts as art. The issue is that the level of selectivity is so much smaller (in a painting, it's 100% both on subject but on every single detail). With that little selectivity, does it really convey metaphysical value-judgments? And even if it does, how effective is it?
Other forms of art include dance, which you can consider a derivative of music. Or singing, another derivative of music. Architecture might be a variant of sculpture, where the building itself conveys metaphysical value-judgments. And there are probably others.
There are always questions about whether a particular form really is art. The question can only be answered by reference to the purpose of art, how much selectivity is really possible, and accordingly whether metaphysical value-judgments are possible.