A work in progress! Feel free to add to, edit, etc.
This information applies to intellectual property in the United States.
Kinds of Intellectual Property
Copyright
Definition adapted from US Copyright Office: A form of protection for "original works of authorship", including literary, dramatic, musical, architectural, cartographic, choreographic, pantomimic, pictorial, graphic, sculptural, and audiovisual creations. "Copyright" literally means the right to copy but has come to mean that body of exclusive rights granted by law to copyright owners.
Computer code is considered to be written work and falls under copyright.
Also good to know: Copyright is attached to work as soon as it is created, there is no need to register content. Copyright holders can transfer copyright to another entity either temporarily or permanently.
Trademark
A trademark protects image/identity. While names and titles are not eligible for copyright, an entity can register a name, logo, or elements of brand identity, which would prohibit other entities from using the same or similar elements for their own uses. This is typically understood to apply to players in competition with the trademark holder, unrelated or coincidental uses of trademarked elements may not be prohibited.
Patent
Patents protect inventions, which might include products or processes. Patents are ostensibly granted to things that are unique or original in some way. While several people might come up with an idea at the same time, patents are granted to the first registrant, and prevent others from using that object or process without permission from the patent holder. Designs/schematics that are registered with the patent office are available to the public. Some companies keep their designs or product designs secret, known as trade secrets instead. Example: the recipe for Coke-a-Cola could be patented, but is not.
Helpful to know
Works for hire assign rights to an employer rather than a creator.
Works in the Public Domain have no copyright restrictions.
Orphan works are covered by copyright, but a copyright holder may not be identifiable.
Helpful Websites & Organizations
(in progress)