In terms of Pluripotent and Totipotent Stem Cells Definition have a look at the following below:
Totipotent stem cells. These are the most versatile of the stem cell types. When a sperm cell and an egg cell unite, they form a one-celled fertilized egg. This cell is totipotent, means that it has the potential to give rise to any and all human cells, such as brain, liver, blood or heart cells. It can even give rise to an entire functional organism. The first few cell divisions in embryonic development produce more totipotent cells. After 4 days of embryonic cell division, the cells start to specialize into pluripotent stem cells.
Pluripotent stem cells. These cells are like totipotent stem cells in that they can give rise to all tissue types. Unlike totipotent stem cells, however, they cannot give rise to an entire organism. On the fourth day of development, the embryo forms into 2 layers, an an outer layer which will become the placenta, and an inner mass which will form the tissues of the developing human body. In fact, these inner cells, though they can form nearly any human tissue, cannot do so without the outer layer; so are not totipotent, but pluripotent. As these pluripotent stem cell continue to divide, they begin to specialize further. Great post related can be read stem cell research facts and here.