Landsat 8 has additional bands. These are a coastal aerosol band (band 1), a cirrus cloud detection band (band 9), and two thermal bands (bands 10 and 11). The bands in Landsat 8 are also within different ranges of the electromagnetic spectrum. Therefore you may need to select different band combinations for display purposes. You can also visit the USGS Landsat FAQs for more information about these differences.