Colcoscopy today & told pre cancerous cells

Hi I had my colcoscopy today which I personally found painful so I received more anaesthetic during the loop treatment. The consultant said I have pre cancerous cells and he also took a biopsy of the lining of my womb. He advised I would have my results in around 4 weeks. I was a bit in shock so I didn’t ask the right questions? Is pre cancerous cells different from abnormal cells? Xxx