It becomes the embryo proper and some extra-embryonic membranes. First it specializes into an epiblast and hypoblast. The epiblast becomes the embryo proper and the hypoblast becomes the yolk sac.

That is the correct spelling of "cytoplasm" (inner fluid mass of a cell).

Inner Cell Mass

In mammals, the blastula forms the blastocyst in the next stage of embryonic development. Here the cells in the blastula arrange themselves in two layers: the inner cell mass and an outer layer called the trophoblast . The inner cell mass is also known as the embryoblast; this mass of cells will go on to form the embryo. At this stage of development, the inner cell mass consists of embryonic stem cells that will differentiate into the different cell types needed by the organism. The trophoblast will contribute to the placenta and nourish the embryo

Inner cell mass