Bit (b): A bit is the smallest unit of data and can represent a binary value of either 0 or 1. It is commonly used in digital communication and storage systems to represent the most basic unit of information.

Byte (B): A byte consists of 8 bits. It is the fundamental unit of storage in most computer systems. Bytes are used to represent a single character of text or a small amount of data. For example, the ASCII encoding system uses 1 byte to represent a single character.

Kilobyte (KB): 1 kilobyte is equal to 1,024 bytes (2^10). It is often used to measure the size of small files, documents, or text. For instance, a plain text document might be a few kilobytes in size.

Megabyte (MB): 1 megabyte is equal to 1,024 kilobytes (2^20) or approximately 1 million bytes. Megabytes are commonly used to measure the size of files, images, audio, or video clips. For example, a high-resolution photo captured by a digital camera can range from a few megabytes to tens of megabytes.

Gigabyte (GB): 1 gigabyte is equal to 1,024 megabytes (2^30) or approximately 1 billion bytes. Gigabytes are frequently used to measure the size of larger files, such as high-definition videos, software applications, or large datasets. For instance, a DVD can hold up to 4.7 gigabytes of data.

Terabyte (TB): 1 terabyte is equal to 1,024 gigabytes (2^40) or approximately 1 trillion bytes. Terabytes are commonly used to measure the size of extensive data collections, such as multimedia libraries, database systems, or backups. For example, a hard drive used for personal storage might have a capacity of 1 or 2 terabytes.

Petabyte (PB): 1 petabyte is equal to 1,024 terabytes (2^50) or approximately 1 quadrillion bytes. Petabytes are typically used to measure the size of large-scale data repositories, such as those found in scientific research, cloud storage, or enterprise-level systems. For example, a large social media platform may handle several petabytes of user data.

Exabyte (EB): 1 exabyte is equal to 1,024 petabytes (2^60) or approximately 1 quintillion bytes. Exabytes are associated with massive data storage and processing environments, such as high-performance computing, big data analytics, or large-scale archival systems. For example, the estimated total storage capacity of the internet was around 1 exabyte in 1993.

Zettabyte (ZB): 1 zettabyte is equal to 1,024 exabytes (2^70) or approximately 1 sextillion bytes. Zettabytes represent an enormous amount of data and are beyond the scale of most conventional storage systems. However, as data generation continues to increase exponentially, zettabyte-scale storage is becoming more relevant in certain domains.

Yottabyte (YB): 1 yottabyte is equal to 1,024 zettabytes (2^80) or approximately 1 septillion bytes. Yottabytes are an extremely large unit of data size and currently exceed the storage capacities available today. It is often used theoretically to discuss the potential future growth of data.