Technologie :
Smartphones
Streaming and downloading
Netflix

1. Streaming and downloading

Streaming and downloading are two ways you can access digital media content (photos, music, videos). These terms are not interchangeable, they actually describe two different processes.

• Dowloading is connecting a device to the source of the file, then copies and saves it to your hard drive. The downloaded file can be streamed to other devices once it has been saved.

• Streaming describes the act of playing media on one device when the media is saved on another.

A streamed file plays from other sources. The source of the media must be connected and turned on, or the streaming stops.

You watch and listen to streaming video and music as it comes to your computer or network media player.

A streaming file is never saved on your device.

Streaming media can be either free, as it is on some network channels; or to be charged a monthly subscription to access the media, such as with Netflix or you rent the video for a certain length of time, after which it is no longer available without renting it again.

Netflix is an online movie rental service. Started in California in 1997, It allows members to rent movies on DVD or Blu-ray. It rent also watching movies and TV shows online with a computer, game console, smartphone, or Internet-connected TV.


2. DVD and Blu-ray Disc

1. DVD

DVD stands for Digital Versatile Disc, or Digital Video Disc. They are read with a laser. There are two kinds of DVD: Single layer and dual layer.

A DVD is an optical disc capable ofstoring up to 4.7 GB of data, more than six times what a CD can hold.

DVDs are often used to store movies at better quality than a VHS (Video Home System: casette).

The disc can have one or two sides, and one or two layers of data per side; the number of sides and layers determines how much it can hold. A 12 cm diameter disc may have a storage capacities ranging from 4.7 gigabytes (GB) for a DVD-5: single sided, single layer; to 17.1 GB for a DVD-18: double sided, double layer on both sides.

2. Blu-ray Disc

Blu-ray Disc is a high-density optical disc format similar to DVD. Blu-ray is the type of disc used for PlayStation 3 games and for playing high-definition (HD) movies.

A dual-layer Blu-ray disc can store up to 50GB (gigabytes) of data. This is over five times the capacity of a DVD, and over 70 times more than a CD or VCD.

A Video CD or VCD is a CD that contains a movie instead of music or a computer program.

The disc was developed by the Blu-ray Disc Association (BDA). a group of consumer electronics, personal computer and media manufacturers. The format was developed for recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data.