Here's a quick look at computer memory sizes. 
A quick note- it's not in units of 1000, as the metric nomenclature would suggest, but 1024. 
Therefore a kilobyte is not 1000 bytes but 1024 bytes.

  
The smallest unit of measurement- either a 0 or 1.  
Bit  

 
This unit, eight bits, is the minimum for one character.  
Byte  8 Bits 

 
This unit is 1,024 Bytes.  
Kilobyte  8,192 Bits
1,024 Bytes 

 
This unit is 1,024 Kilobytes.  
Megabyte  8,388,608 Bits
1,048,576 Bytes
1,024 Kilobytes 

 
This unit is 1,024 Megabytes.  
Gigabyte  8,589,934,592 Bits
1,073,741,824 Bytes
1,048,576 Kilobytes
1,024 Megabytes 

 
This unit is 1,024 Gigabytes.  
Terabyte  8,796,093,022,208 Bits
1,099,511,627,776 Bytes
1,073,741,824 Kilobytes
1,048,576 Megabytes
1,024 Gigabytes 

 
This unit is 1,024 Terabytes.  
Petabyte  9,007,199,254,740,990 Bits
1,125,899,906,842,620 Bytes
1,099,511,627,776 Kilobytes
1,073,741,824 Megabytes
1,048,576 Gigabytes
1,024 Terabytes 

 
This unit is 1,024 Petabytes.  
Exabyte  9,223,372,036,854,780,000 Bits
1,152,921,504,606,850,000 Bytes
1,125,899,906,842,620 Kilobytes
1,099,511,627,776 Megabytes
1,073,741,824 Gigabytes
1,048,576 Terabytes
1,024 Petabytes 

 
This unit is 1,024 Exabytes.  
Zettabyte  9,444,732,965,739,290,000,000 Bits
1,180,591,620,717,410,000,000 Bytes
1,152,921,504,606,850,000 Kilobytes
1,125,899,906,842,620 Megabytes
1,099,511,627,776 Gigabytes
1,073,741,824 Terabytes
1,048,576 Petabytes
1,024 Exabytes 

 
This unit is 1,024 Zettabytes.  
Yottabyte  9,671,406,556,917,030,000,000,000 Bits
1,208,925,819,614,630,000,000,000 Bytes
1,180,591,620,717,410,000,000 Kilobytes
1,152,921,504,606,850,000 Megabytes
1,125,899,906,842,620 Gigabytes
1,099,511,627,776 Terabytes
1,073,741,824 Petabytes
1,048,576 Exabytes
1,024 Yottabytes