A lysosome is a cell organelle. They are like spheres. They have hydrolytic enzymes which can break down almost all kinds of biomolecules, including proteins, nucleic acids, carbohydrates, lipids, and cellular debris. They contain more than 50 different enzymes.
By convention, lysosome is the term used for animal cells. In plant cells, vacuoles do similar functions. With a wider definition, lysosomes are found in the cytoplasm of plant and protists as well as animal cell.
Lysosomes work like the digestive system to break down, or digest, proteins, acids, carbohydrates, dead organelles, and other unwanted materials. They break up larger molecules into smaller molecules. Those smaller molecules can then be used again as building blocks for other large molecules.