What is the difference between volume and partition?

What is Partition?

A hard disk drive can be divided in to several storage units called partitions. The main partitions that could be created in a hard disk drive are primary, extended and logical partitions. A disk drive can contain a maximum of four primary partitions or three primary partitions and a single extended partition. One file system is contained in a primary partition. When there are multiple primary partitions in a hard disk, only a single partition can be active at any given time and the other partitions will be hidden. If a drive needs to be bootable, it needs to be a primary partition. Information about the partitions in a computer is included in the Partition table, which is located in the Master Boot Record. The extended partition in a hard disk drive could be subdivided in to several partitions called logical partitions. The extended partition acts as a container for logical partitions. The structure of the logical portions is described using one or more Extended Boot Records (EBR). Creating partitions would allow the user files to be resided separately from the operating system and other program files. Furthermore, partitions would allow the user to have multiple operating systems to be installed in different partitions of the same hard disk.

What is Volume?

A storage area that could be accessed using a single file system that the computer can recognize is referred to as a volume. This term is used in the context of operating systems. CDs, DVDs and some partitions of the hard drive can be considered as volumes. When the operating system recognizes a volume, the data within that volume can be accessed. Moving files within a volume is typically done by just modifying the file system (without doing any physical alteration). However, when data is moved between volumes the actual data has to be moved, which would be a costly operation.

What is the difference between Primary Partition and Extended Partition?

Storage units that could be divided within a hard disk drive are called partitions whereas a storage area that could be accessed using a single file system that the computer can recognize is referred to as a volume. 【Therefore CDs, DVDs and floppy disks could be considered as volumes】. Furthermore, if a hard disk contains partitions that were formatted using a file system that could not be recognized using the operating system, such a partition could not be considered as a volume.

Once a Partition is formatted and given a drive letter is is called a Volume. This can be a physical volume (on one partition of a physical disk) or a logical volume (which sits on RAID Partition for instance that spans multiple physical hard drives).

总结：

partition 分区，是针对磁盘的概念，是物理层面的概念。我们买回一块磁盘，可以对它进行分区，将一块磁盘划分为几个独立的存储单元，买回1块大磁盘=买回几块小磁盘。但磁盘需要格式化后才能被操作系统识别和读写，分区只是把大磁盘变成多块小磁盘，仍然是没有格式化的，电脑的操作系统是不能往里读写文件的

volume，是针对操作系统的概念，是逻辑层面的概念。对磁盘分区后，我们对各个分区进行格式化以在分区上形成文件系统（file system）如exfat, fat16, fat32, NTFS（现在我们Windows操作系统一般使用NTFS）等等，然后就能读写了。【格式化后能够被操作系统读写的partition叫做volume】
一个volume可以由一个或多个格式化后的partition组成

一般而言，windows内常见的c、d、e盘都是volume

自上而下的逻辑结构如下：

   os
   |
file system
   |
 volume
   |
partition(s)

reference: https://www.quora.com/What-is-the-difference-between-volume-and-partition