Wounds are injuries to the skin or tissues that range from minor cuts to severe damage. Wounds can be classified based on their cause, depth, and other characteristics such as open wounds like incisions, lacerations, abrasions, and punctures or closed wounds like contusions. Wounds can also be classified as superficial, partial thickness, or full thickness based on depth and as clean, contaminated, or infected based on the degree of contamination. The phases of wound healing are inflammation, proliferation where new tissue is formed, and remodeling/maturation where scar tissue forms over months. Factors like nutrition, blood supply, infection, age, and diseases can affect the wound healing process.