LGBT Pride Month is a month dedicated to the celebration and commemoration of lesbian, gay, bisexual, and transgender (LGBT) pride. Modern-day Pride Month both honors the movement for LGBT rights and celebrates LGBT culture. 

When is it celebrated?: June

Origins: Pride Month began with the Stonewall riots, a series of riots for gay liberation that took place over several days beginning on June 28, 1969.

Who started it?: Bisexual activist, Brenda Howard, is known as the "Mother of Pride", for her work in coordinating the first LGBT Pride march.

LGBTQ+ definitions

• Lesbian: A person who identifies as a woman and experiences attraction to the same sex and/or gender

• Gay: A person who experiences attraction to people of the same sex and/or gender. Includes people who identify as either men or women and refer to those who identify as men only.

• Bisexual: A person who experiences attraction to both men and women.

• Transgender: A person whose gender identity does not correspond with the gender and/or sex assigned at birth.

• Queer :This term has a history of being used as a derogatory, homophobic, and transphobic slur but has been reclaimed by some LGTBQIA2S+ communities as a term of pride and positivity, and diversity. It is used to encourage a broad spectrum of identities related to sex, gender, and attraction.

• Cisgender: A person who identifies with the gender associated with the sex they were assigned at birth, in line with dominant social expectations.

• Non-Binary: Someone who identifies as non-binary may identify with elements of both man and woman, with another gender, or no gender at all.

 From Wikipedia