what are cDNA libraries? how they are made

Hello Student

A cDNA or complimentary DNA library is the combination of complimentary DNA fragments which inserted into the host cell, which together constitute some portion of transcriptome (set of all RNA molecules inclucing mRNA, tRNA, rRNA etc.) of the organisms.
these are made by

1. fistly we isolate and collect the mRNA
2. then we done reverse transcriptase
3. and the formed DNA are introduced plasmid of bacteria
4. these plasmids are introduced into bacterial cell such as E.coli
5. then grow them
6. isolate plasmid and purify DNA the we have the sequence.