In the past only one sexuality - heterosexuality - was viewed as appropriate but today there are multiple sexual orientations that are recognised by mainstream society and considered normal by cultural standards as well as international mental health organizations.
Heterosexuality, homosexuality, bisexuality and questioning are all sexual orientations that appear on the sexuality spectrum, and recognising and coping with whichever sexual identity you identify with is an important part of maturing into an adult.
Heterosexuality
Statistically, heterosexuality is the most common sexual orientation in the world today. Heterosexuals are sexually attracted to others of the opposite sex (male heterosexuals are attracted to females and female heterosexuals are attracted to males), and their sexual activity is usually limited to interactions with the opposite sex.
Homosexuality
Homosexuality is perhaps the main minority sexuality in the world, though gathering statistics on this can be difficult. Homosexuals are sexually attracted to others of their own sex (male homosexuals are attracted to other males, and female homosexuals, often called lesbians, are attracted to other females), and their sexual activity is usually limited to interactions with the same sex. Sometimes homosexuals are also called "gay" or "lesbian".
Bisexuality
Bisexuality is a unique sexual orientation which many heterosexuals and homosexuals don't even fully recognise. Bisexuals are sexually attracted to others of either sex (male bisexuals are attracted to other males as well as females, and female bisexuals are attracted to other females as well as males), and their sexual activity is not limited to either sex.
The intensity of attraction to males or females is particular to each bisexual, though many bisexuals say that they are more often attracted to a particular sex but can occasionally become attracted to specific individuals as well.
Questioning
Individuals who are questioning their sexuality are exploring their sexual attraction to others and trying to make sense of their feelings and patterns. These individuals are reluctant to classify themselves as having any particular sexual identity, and instead embrace the fluidity of their attractions whenever and with whoever they occur.
Coping with Any Sexuality
Recognising and coping with any sexuality can be embarrassing, frustrating and ultimately bring a lot of stress into a person's life. Many people simply assume that they are heterosexual because it is the predominant sexual orientation today, and it is only later that they realize that in fact they are homosexual, bisexual or questioning. Coping with sexuality can be tough, but it can be easier if you enter into therapy.