Today’s most prevalent sequencing technology for sequencing genome is illumine sequencing. Illumine operates via preparation of the libraries with short reads depending on the platform of the illumine which the read length can differ. The early machines were able to operate with read length around 50 bp. The further development in the system makes it possible to read higher read length till around 750 bp. To this extent we would have our genome in a high number of sequenced pieces. The longer the read is, the better would be the result of assembly since there are many repeats in the genome with different length and the longer reads has lower probability of un-unique positioning of related reads. Through assembly you can put the reads in the right order. There are different sequencing technologies and different Next Generation machines. The precision in this sequencers are also high, based on what they have been claimed is about 99.9% for majority of their reads.