The term 'โดย (dooy)' in Thai is used to highlight the means or way by which an action is performed or a state is achieved. It is similar to the English prepositions 'by', 'via', 'with'. It indicates the approach, manner, or method involved in carrying out an action. This word is versatile and can be used in various contexts ranging from transportation means, method to complete a task or how a result is achieved.