Is Ovule and Embryo Sac Same?

Embryo sac is a part of ovule.

Is embryo sac called ovule?

Plant Physiology and Development

In Arabidopsis, the mature ovule contains the megagametophyte (embryo sac) that comprises two female gametes, egg cell and central cell, two synergid cells, and three antipodal cells, which are surrounded by the maternal integuments.

What is another name for the embryo sac?

The female gametophyte—specifically termed a "megagametophyte"—is also called the embryo sac in angiosperms. The megagametophyte produces an egg cell for the purpose of fertilization.