With [TH] Reactions you able to control how you want your reactions to work. Rather it be the icon, image, color, or if it shows a negative outcome. Configure which reactions can send alerts, publish into the newsfeed, which reactions can be undone by the users, and how many reactions can be used per day.
With reaction types, you can choose what order the reaction type will appear in to the user.
Choose what order the reaction type will appear in to the user while also changing if they are positive, negative, or neutral.