The term "70S" typically refers to a specific type of ribosome found in prokaryotic cells, such as bacteria. Ribosomes are essential cellular structures responsible for protein synthesis. The "S" in "70S" stands for Svedberg units, a measure of sedimentation rate, which reflects the size and density of the ribosome. The 70S ribosome is composed of two subunits: the smaller 30S subunit and the larger 50S subunit. In contrast, eukaryotic cells, like those in plants and animals, contain 80S ribosomes, which are larger and have different subunit compositions. The distinction between 70S and 80S ribosomes is important in molecular biology and antibiotic development, as certain antibiotics target bacterial ribosomes without affecting eukaryotic ribosomes.