I have one basic doubt about Rna seq analysis. In some tutorial they have used linux for analysis but some they followed bioconductor packages. How are these two approaches are different? Moreover, can anyone suggest useful sites to learn NGS Data analysis and online free courses to learn
Generally, raw NGS data is first processed using one of the many popular command line tools (linux) or Galaxy. Statistical analysis followed by further downstream analyses can then be done in a scripting language like R/bioconductor or python. There are several online resources for NGS data analysis. The courses in the Genomic Data Science track on Coursera cover a lot of the different aspects and approaches to NGS analysis: https://www.coursera.org/specializations/genomic-data-science
See the courses titled "Command Line Tools for Genomic Data Science" for an introduction to the linux based tools for NGS, and "Bioconductor for Genomic Data Science" for further processing in bioconductor if you're interested in these areas. Hope this helps.