The Physical Age
Data you could hold. Binary encoded as holes punched through cardboard. Sequential processing only.
Physical Reality
80 columns, 12 rows. Light shines through holes to read bits. Drop the deck and lose your data order.
The Magnetic Age
Data encoded as magnetic particles on tape. Sequential access only—rewind to start.
Physical Reality
Iron oxide coating on plastic tape. Hierarchical and network models emerge. Physical pointers = physical addresses.
The Spinning Disk Era
The birth of random access. Read heads fly nanometers above platters spinning at 7,200 RPM.
Physical Reality
Magnetic domains on aluminum platters. B-tree indexes enable SQL. RAID arrays provide redundancy.
The Flash Revolution
No moving parts. Data stored as trapped electrons in silicon. Speed becomes the priority.
Physical Reality
NAND flash cells trap electrons in floating gates. 3D stacking puts terabytes in your pocket.
The Cloud Era
Data becomes ethereal. It exists everywhere and nowhere—distributed across the planet in milliseconds.
Physical Reality
Object stores chunk data across thousands of drives. Erasure coding provides durability. You never see the hardware.