Different grades of sequencing are basically down to the technology and depth. The short read sequencing you're describing makes reads that are like motes of d

Different grades of sequencing are basically down to the technology and depth. The short read sequencing you're describing makes reads that are like motes of dust in comparison to the genome. More modern long read methods can read off sequences with high accuracy and/or length. These tend to be much higher in cost and substantially higher in the completeness and quality of the resulting bioinformatically inferred genome.