Megabytes can be thought of in terms of music or Word documents: A single 3-minute MP3 is typically roughly 3 megabytes; a 2-page Word document (only text) is about 20 KB, thus 1 MB would carry approximately 50 of these. Gigabytes, which is probably the most recognizable size to you, are rather large. It takes about 18 million MP3 files to reach a gigabyte, and a single high-quality digital photo is about 4 MB.
A medical imaging study such as an MRI or CT scan can be several hundred MB or larger. An hour-long movie usually ranges from 2 to 10 GB, depending on its quality and complexity. An entire album of mp3 music tracks will be about 70 MB.
1 MB is a big file! It takes up a lot of space on your computer hard drive and may not be able to be saved if you want to keep your current file structure. We will discuss ways to reduce the size of a file below.
One megabyte is equal to one million bytes (or about 1000 kilobytes). A few minutes of MP3 audio or a ten million pixel image from a digital camera would normally take up a few gigabytes. One megabyte is a lot of memory!
The first computer I ever worked on had 16 MB of RAM. That made it very expensive back in 1992! A standard desktop PC today will have at least 256 MB, and many have more than that. 10 years ago, the most common type of memory used in PCs was 64 MB DRAM, but now laptops mostly use 300-500 MB hard drives instead. Memory technology has come a long way since 16 MB!
In fact, one megabyte of memory today is almost exactly the same size as one megabyte of memory did in 1987! They're both 1024 kilobytes.
There are different ways of measuring memory usage. Some applications count the number of bytes they allocate using functions such as malloc. Others count the number of objects they create using functions such as new. Still others count the number of words in data structures such as lists or dictionaries.
For our purposes here, we'll simply assume that one megabyte of memory contains enough space for us to store one million bytes of information.
1 GB can store around 640 pictures, 240 MP3 files, 19200 Word documents, or 320 minutes of video. The total amount of storage available on a GB device is 100%.
A full disk drive is currently the most efficient way to store data. A disk drive with Gb capacity can store about 690,000 images, 240 MP3 songs, 19,200 Word documents, or 3 million characters using only its main memory. The next largest category of storage devices are USB flash drives which can store up to 16 TiB of data.
The number of bits that can be stored in a binary digit (bit) is limited to 2 levels or states: 0 and 1. A bit can either represent a "0" or a "1". A bit string of length n will contain 2^n different values. For example, for n = 4, there are 256 possible values for a string of four bits. There are only 24 possible values when n = 3: 000, 001, 010, 011, 100, 101, 110, 111.
A byte is the basic unit of storage in bytes. One byte can store up to 7 bits because each bit can have one of two values.
Storage and memory in today's world are frequently measured in megabytes (MB). A medium-sized novel has around 1 MB of data. Not one million bytes, but 1,024 kilobytes, or 1,048,576 (1024x1024) bytes. This number is generated by the fact that computers employ binary math. Each byte is a sequence of eight bits, which can be either 0 or 1.
In scientific notation, this is written as 1 KB = 1,024 bytes. There are 1,073,741,824 bytes in 1 GB.
The human brain contains about 100 billion neurons and 10^12 connections between them. At any given time, each neuron will typically have 10,000 channels open with other neurons. That's 10 PB of information that must be stored somewhere!
A computer's RAM is much more limited - it usually only has several gigabytes worth of storage. However, computers use much more efficient methods for storing data than humans do. Humans create pointers from our memories to these other places where we store information, but computers have hardware devices called "drives" or "disks" that act as giant caches of previously accessed files.
So, yes, 1 MB is exactly equal to 1,048,576 bytes.
GB is an abbreviation for gigabyte, which is equal to 1024 megabytes (MB) or 1,048,576 kilobytes (KB). As an example, 1 GB of data would allow you to accomplish one of the following: Watch one hour and twenty minutes of standard definition video. Approximately eight hours of high-quality music may be streamed (320 kbps). One full day of ordinary Internet use includes about 3,500 bytes of transfer. That's why computers have more than a million bytes of storage space available to them.
8 GB is a large amount of memory. Computers with this much memory usually cost more than $10,000. Some desktop computers have up to 128 GB of memory. That's 16,777,216 bytes or 1,714,437,456 bits.
Compared to 1 GB, 8 GB of memory can store nearly seven times as much information. It's enough memory for about 75,000 high-quality digital audio tracks or 15,000 high-definition videos.
The vast majority of personal computers today come with only a few hundred megabytes of memory, which is far less than what is needed to run most applications today. 1 GB is a good amount of memory for running Windows XP or Mac OS X. More than 1 GB is useful if you want to run several programs at once or store lots of data in memory.
A gigabyte (GB) is about one billion bytes, or one thousand megabytes. A terabyte (TB) is a million gigabytes, or one billion megabytes.
Thus, 1 billion bytes is a large amount of data.
In fact, it's the largest number that can be stored in a 32-bit integer. Because integers are limited to 2^32 = 4,294,967,296 values, any larger number must be represented by more than one integer.
And since a double-precision floating point number can store up to 15 decimal digits, a billion bytes requires around 16 decimal digits which is quite possible given that there are only 10 to the power of 6 = 3125 decimal digits in a standard floating point number.
Here's a chart with some other large numbers and their decimal representations:
1000000000 bytes = 9223372036854775808 bits = 184 decimals
1000000000000 bytes = 9.2233720313685063e+19 bits = 1.8446744073709552e+20 decimals
A megabyte cannot be greater than a gigabyte since one gigabyte equals 1024 megabytes. For reference, this is the scale: A bit (the smallest unit) can only have a value of 0 or 1. (binary). A byte (8 bits) may hold up to 255 integers. A kilobyte is equal to 1024 bytes. (30–100KB) is around the size of a small word document. A megabyte is equal to 1000 kilobytes.
A gigabyte is equal to 1000 megabytes and is almost always displayed with at least three zeros after it. It's considered good practice to write "1 GB" instead of just "GB". A billion bytes is called a terabyte or 1 trillion bytes. Earth's total storage capacity is estimated to be about 590 billion bytes.
Storage devices get smaller every year but we still use terms like "smaller file", "large file", etc. There are no real limits to growth here, but rather a limit based on how small you can go before you start running into technical problems with storage devices. In other words, there's no limit to growth but rather a limit based on cost/size constraints. Writing over 1TB of data would not be common but possible.
The number 1000000 bytes is called a petabyte and is often used as an example of a large file size. One million megabytes is called a terabyte. One hundred thousand gigabytes is called a petatype and is equivalent to about 20 petabytes.