Final answer:
Cells are classified by their layers into simple, stratified, transitional, and pseudostratified, and by their surface cell shapes into squamous, cuboidal, or columnar. Histology studies these aspects to understand how tissues are formed and function.
Step-by-step explanation:
Cells can be classified according to the arrangement into layers and the shape of surface cells. The arrangement into layers can be simple (a single layer), stratified (multiple layers), transitional (in which the shape of the cells can vary and is slightly more complex), or pseudostratified (appears layered due to the varying positions of nuclei but is actually a single layer).
The shape of surface cells can be classified as squamous (flattened and thin), cuboidal (box-like and approximately as wide as it is tall), or columnar (rectangular and taller than it is wide). Histology is the study of the shape and arrangement of cells in tissues, and it is important to understand this to grasp how cells form tissues and the functions they carry out.