Roku ..Sony.. many more
basically a (hardware) media player , is a box that accepts a external hard drive or USB memory stick or network connection and plays your media files directly to the TV thru A/V or HDMI cables
my Sony uses HDMI cable, connects to HD via USB, and will connect to internet via Wifi and plays my stored video OR my Amazon ..NetFlix accounts
when i first got it in early 2012, i used it extensively to watch movies from Amazon on my TV
last year i purchased i "HomeWorx" brand TV tuner/PVR
it records OTA HiDef TV broadcasts in HiDef onto an external drive
it will also play avi and mp4 files stored on the external drive
so i have two ways of watching movies NOT using the DVD player or laptop
std DVD movies are 4gig to 7gig in size
compressed and stored to MP4 they are 1gig to 2gig in size
one hour of really good video is about 1gig
some people compress to a smaller size say 350mb..but that loses quality
a 1TB hard drive can store about 1000hrs at 1gigabyte per hour
or roughly 500 std DVD movies converted to MP4
or 200 ripped full sized NOT compressed copied DVD movie folders