Arborvitae, juniper, and false cypress are all members of the cypress family. However, though they’re related (and frequently confused), there a quite a few differences between them.
Compared to arborvitae, junipers (Juniperus) tend to have more bluish-green foliage, are slower growing, and produce aromatic “berries” that attract birds. While they take longer to grow, they are deer resistant, drought-tolerant, and easier to grow.
False cypress (Chamaecyparis) looks similar to arborvitae but comes in a broader range of textures and colors (like gold and blue). They tend to be smaller and much slower growing, but that might be good, depending on your garden. False cypress is also deer resistant, unlike arborvitae.