The structure of the DNA is a double helix where Cytosine and Guanine connect and Adenine and Thymine connect.
The process of DNA replication is that the DNA breaks into two, separating the ladders so only one set of codes is shown. Then the correct bases(C-G A-T) connect and form a new strand which continues the replication process.
The relationship between DNA and RNA is that, in a sense, RNA is a copy of DNA. However, RNA replaces Thymine with Uracil in the process.
The process of transcription is where RNA and DNA strands are cloned to create a protein code. Translation is where cells use the now RNA to create a protein.
Hope this helps!