1. File types and storage

2. Primary and Secondary storage  Primary – built into the computer, the computers memory capacity  RAM – random access memory (temporary)  ROM – read only memory (permanent)  Secondary – connected by cables or input/output ports  Secondary storage is INDEPENDENT of the computer – for example hard drives and NAS (network attached storage) drives

3. Storage Measurements  Byte – B – 8bits – eg one keyboard character  Kilobyte – KB – 1024 bytes – one page of text  Megabyte – MB – 1024 kilobytes – one full screen image  Gigabyte – GB – 1024 megabytes – 90mins of tunes  Terabyte – TB – 1024 gigabytes – 250,000 songs

4. File Types  When you SAVE files/data a file type is needed. This is so the computer can recognise a related program to open the file  STERO LITHOGRAPHY - STL  RAR – roshal archive format  Batch – text/script  Mp4 –MPEG4 (moving picture expert group)

5. Questions  Why does a computer have PRIMARY and SECONDARY storage?  What is a file extension?  Write a list of ALL the files types you have heard of