Here's a short summary of the story:
One day, a queen pricks her finger and three drops of blood lands in the snow. She wishes for a child with skin as white as snow, lips as red as blood, and hair as black as ebony. Her wish comes true and gives birth to Snow White but she dies during childbirth. The child's father remarries a vain woman. The new wife has a magic mirror that she asks every day "who is the fairest in the land?" The mirror always said her until Snow White turned 7. The new queen hires a huntsman to take Snow White into the forest and kill her. As proof, she asked for Snow's lungs and liver. The huntsman is unable to and brings back the innards of a wild boar instead.
The queen asks the mirror again and finds out Snow is still alive in the dwarfs' cottage. The dwarfs found Snow in their bed after seeing she ate and drank their food. They let her say if she keeps house for them. The queen disguises herself and gives Snow White a bodice. She laces it so tight that Snow can't breathe and she faints. The dwarfs return in time to revive her. Next time, the queen gives her a poisoned comb. The dwarfs save her again. The third time, she gives Snow an apple dipped half in poison. She takes a bite of the other half to prove it's safe. Snow takes it and dies.
The dwarfs don't know how to save her and put her in a glass box. A prince sees Snow White and asks the dwarfs for the coffin. As they are carrying her away, they jostle the box and the apple falls out of her throat. The prince proposes to her.
They invite everyone to the wedding including the evil queen. The queen goes to the wedding and is shocked to see Snow there.
For her attempted murders, she is given hot iron shoes and forced to dance until she dies.
Like all Grimm fairy tales, there is a dark ending.
In other adaptations (a 1912 play), the dwarfs are given names.
Influences: Karlheinz Bartels published an analysis suggesting that Snow White was based on the life of Maria Sophia Margaretha Catherina von Erthal. She was described as an angel, her step mother abused her, her father worked for the Prince, the stepmother cared more for her own children, and was given a mirror as a wedding gift. The stepmother gave her an apple half submerged in belladonna juice. Unfortunately, she had no prince to save her from her death.