Tissue culture, organ culture and cell culture?

[forumer]

1. What is the difference between Tissue culture, organ culture and cell culture?

2. And when we talk about transformation in mammalian cells, does it mean that we transform the cells into cancer cells?

3. What does it mean when it says in the context of selection of serum and medium: "Established cell lines- Simple media- Eagle’s MEM + serum" ? What are established cell lines?

Thanks for any ideas.

[Credence]

Cell culture is growing undifferentiated cells in media ( liquid/solid) .
Tissue or Organ culture is growing cells in re-differentiated stage of Plants and animals respectively.