A 5' cap and a 3' poly-A tail must be added. Then the pre-mRNA must be spliced. After this it is called mRNA and is ready to be transported to the cytoplasm for translation.
After being transcribed from DNA, the pre-mRNA is reduced in size by having nonexpressed sequences, called introns, cut out from it. The remaining expressed sequences, called exons, are then spliced...
The first (primary) transcript from a protein coding gene is often called a pre-mRNA and contains both introns and exons. Pre-mRNA requires splicing (removal) of introns to produce the final mRNA...