Wound condition changes from moment to moment. It is important to understand what is happening on the wound to evaluate and treat it. Wound can be classified into low contaminated wound, contaminated wound, colonized wound, critical colonized wound and infected wound by status of bacteria on the wound. Moreover, it can be classified into acute wound, subacute wound, subchronic wound, and chronic wound by time course. Also, wound healing course can be classified into coagulation phase, inflammation phase, proliferation phase and remodeling phase. Moreover, wound healing can be classified into primary wound healing, secondary wound healing and tertiary wound healing according to types of surgical intervention. The TIME principles provide a systematic approach to the management of wounds. TIME leads to an optimal wound bed preparation( WBP). The objectives underpinning TIME are tissue non-viable or deficient (T), infection or inflammation (I), moisture imbalance (M) and epidermal margin;non advancing or undermined( E).