Joint pain is a type of discomfort that can occur in any joint. Arthralgia is the medical term for joint pain. This is distinct from arthritis, which is defined as joint inflammation characterised by pain, warmth, redness, and/or swelling of the joint. A joint might be painful even if it isn't inflamed, or it can be painful and inflamed at the same time.
Joint pain can affect a single joint or a number of distinct joints. The underlying reason will determine the pattern of joint pain in terms of how many and which joints are impacted.