Why fastq?

So far, you have been introduced to the ShortRead package with useful tools for the initial stages of short-read sequence analysis. As a summary, the main functionalities of this package are:

• Data input
• Quality assessment
• Data transformation
• Access to downstream analysis

In this context, you have been exposed to two different file types: fasta and fastq.

What do you think is the reason to use fastq formatted files?