While studying the history of the discipline of acting, it is important to know the history of women as actors in Ancient Greek theatre.

Women were not permitted to act in Ancient Greek theatre. In fact, women did not gain acceptance into the theatrical world until the 17th century. As you probably know, women were-and in some parts of the world, still are-regarded as second class citizens.
Since women had no roles in theatre of that time, men had to play the female parts. Often, a younger male would play the role of women in hopes of at least somewhat disguising their voice.
As we said, men would play the roles of women. However, it is difficult to completely disguise a male as a female. Therefore, masks were a very important part of the Ancient Greek theatre experience. Pretty much all plays involved the actors wearing masks. A primary reason for this costume effect was so that the male characters were more believable as females.
Another interesting component associated with the masks is the development of tragedy and comedy. Frequently, the audience would find out what shows they were going to see when they arrived at the performance. If a person with a sad mask came out, they knew that they were going to see a tragedy. On the other hand, if the characters adorned happy masks, the audience knew that a comedy was on its way.
Theatre evolved throughout the years, and now women are able to perform just as fully in performances as men are. However, the two important genres of tragedy and comedy have made their mark on the theatrical world.