The whole world has an ecosystem, where plants play the role of producers and animals play the role of Consumers. Hence their activities and differences along with cell structure. Well, before that, one should know that a cell is a fundamental unit and all cells carry all the activities.
A heterotroph is a term given to animals since they are not able to make food on their own and they depend on plants for food. Whereas plant cells are autotrophs since they can make their food.
Plant cells can make their food since their cell has a cell organelle called chloroplast that performs the process of photosynthesis. Like this, many organelles are present in animals but not in plants and vice versa.