Ribosomes are small organelles that can be found attached to the rough endoplasmic reticulum (ER) or free-floating in the cytoplasm. Ribosomes help to transcribe DNA in order to make proteins.
Proteins are involved in many cell functions- building blocks for cellular structures, repairing damage, building tissues, directing chemical processes, creating enzymes to speed up the rate of chemical reactions, etc. As you can see, proteins are an essential part of life in both eukaryotic and prokaryotic cells. Thus, ribosomes are are extremely important to the survival of living things.
The location of the ribosomes determines what kind of proteins are created. If the ribosomes are free-floating in the cytoplasm, then they make proteins that are used solely within the cell. If the ribosomes are a part the ER, then they make proteins that are used in or out of the cell.