Gigabytes, Terabytes or Petabytes, how big are they?

When we have to buy a new external hard drive or a computer we often hear about gigabytes, terabytes or megabytes. Here's what they mean

When we read about the size of the internal memory of a device or the size of a file we will have heard terms like megabyte or gigabyte. But there are also terabytes or petabytes. For those who do not have great computer skills, however, it is not always easy to understand what these words mean.

It may seem a trivial information, but instead understand how many gigabytes or how many terabytes of memory can hold a hard drive is essential to buy the right accessory for our PC. And the same is true when we want to buy a new smartphone or a new notebook. As you may have guessed, terabytes, petabytes, gigabytes or megabytes, are all terms used to indicate a unit of measurement multiple of the byte. Con il termine byte invece in informatica si indica un’unità di misura di informazione di 8 bit.

Da byte a yottabyte

Il byte è la quantità di archiviazione necessaria per memorizzare un singolo carattere di testo. E quindi è l’unità di misura più piccola rispetto a tutte le altre. Poi troviamo il kilobyte, che altro non è che 1.024 byte. A seguire ci sono i megabyte (106 byte) e i gigabyte (109 byte). Ancora più grande è il terabyte che corrisponde a 1.024 gigabyte. Poi troviamo i petabyte (1015 byte) e l’exabyte (1018 byte). Di dimensioni ancora maggiori sono lo zettabyte (1021 byte) e lo yottabyte (1024 byte).

Quale scegliere

Al momento se vogliamo comprare un hard disk esterno, ma anche se ci avviciniamo all’acquisto di un nuovo computer, l’unità di misura da prendere in considerazione è il terabyte. Come detto al suo interno ci sono1.024 gigabyte. Taking advantage of a TB we can store the contents of 1,498 CD-ROMs. If we reason in terms of photos instead we would need 130 thousand shots to fill our storage. In practice we will have at our disposal almost 400 photos per day for a year. Currently on the market hard disk solutions economic and mid-range range between 1TB and 3TB. And what about gigabytes instead? One GB can store nearly 300 songs in MP3 format. A movie downloaded from Netflix requires at least 4GB of space, if it is in 4K even 20GB. New smartphones have storage between 32GB and 128GB.

Bigger formats

Petabytes and exabytes are unlikely to interest ordinary consumers, however there are some very interesting facts about them. For example, scientists estimate that the human brain can store up to 2.5PB of data. To save the graphic animations of the movie Avatar instead was used more than 1PB. To give an idea of its size with a petabyte we can save more than 4 thousand photos per day for our entire life. What about exabytes? Are they impossible to reach? Wrong, in 2010 the Internet in a single month managed about 21EB. According to some scientists one gram of DNA can hold 490 exabytes.