sexism is the act of discrimination and sexual objectification, is when you reduce someone or a group just by gender or sexual orientation.
One of the most common cases of sexism is to stipulate that the color pink is related to the female gender, and blue to the male gender.
Sexism is usually associated with the position that machismo determines for women. But it can also be related to the prejudiced treatment given by society to men, homosexuals, transgender, to those who do not identify with any of the genders, among other forms of identity representation sexual.
Women and men can have sexist attitudes. Some lines of studies on gender even suggest the use of the term sexism to replace the word machismo, so that the negative characteristic of machismo is not something only associated with men, or something inherent to the fact of being of the gender masculine.
The word sexism meets synonyms in its variations according to the treated genre. Discrimination against women is machismo or misogyny, while the prejudice against men is called misandry.
What is it to be sexist?
One of the ways of problematizing a situation and realizing whether or not there is sexism in the act is to invert the genders: putting a man to do what is being proposed to a woman. If it causes strangeness, it's sexism.
For example:
Beer advertisements constantly use feminine attributes, relating them to the attributes of beer, as a selling point. Try to reverse the genre explored in the campaign: would it make sense for a man in the same clothes, making the same moves? Would it appeal to the audience the product is intended for? Or would it cause strangeness?
Sexism also acts by stipulating an expected pattern of behavior for men and women. It is equally sexism when you play a man who is always close to heavy machinery, who likes cars, who has rude manners, and so on. The same behavior when the genders are inverted also generates estrangement.
One of the consequences of sexist society is homophobic prejudice, where men are expected to has a certain behavior, and when he does not demonstrate such characteristics, it ends up being discriminated.
See also the meaning of Feminism and gender inequality.