Copyright protects original works of authorship fixed in a tangible medium — software, marketing materials, photographs, manuals, databases to the extent of their original selection and arrangement.
Ownership. The author owns, except that works prepared by an employee within the scope of employment are works made for hire owned by the employer. Contractor work is not, unless it falls within enumerated categories and there is a signed agreement — which is why a present-tense assignment is required in every contractor agreement.
Registration. Not required for protection, but required before filing suit. Registration before infringement, or within a grace period after publication, is what makes statutory damages and attorney fees available. Without it a plaintiff must prove actual damages, which for most business works is small.
Term runs for decades and does not require renewal.
Fair use. A four-factor analysis — purpose and character including whether the use is transformative, nature of the work, amount used, and effect on the market. It is a defence assessed case by case, not a category.
Digital notice and takedown procedures, and the requirement to register an agent to claim the safe harbour for hosted content.
Practical hygiene. Register the works that matter, keep the assignment chain, and license stock and font assets properly.