Label. An optional name that can be assigned to a partition to simplify its
identification. Usually has the same limitation as file names. For example,
FAT partitions have labels up to 11 characters long, but may contain spaces.
Letter (of a drive, partition). All operating systems that are DOS-compatible use
Latin letters to identify drives and partitions. Letters A: and B: are usually
reserved for floppy drives. Starting with C: letters are assigned to hard disk
partitions that can be recognized by the operating system. Separate letters
may be assigned to CD-ROMs, DVDs, or other disk drives, and to network
drives. A very detailed description of the letter assignment order of different
operating systems is given in 2.9 «Assignment of Letters in Different
Operating Systems».
Logical partition. Partition information about which is located not in MBR, but
in the extended partition table. The number of logical partitions on a disk is
unlimited.
Master boot record. See MBR.
Operating system is a set of programs that usually includes kernel, drivers,
shell and system programs that is used for centralized hardware
management and hiding the details of hardware management from the user
and applications.
Operating system booting is initiated by loading its boot sector to memory at
0:7C00h address and passing control to it. Since every operating system has
its own boot sector, it is able to perform all the necessary actions to load and
initialize system and configuration files.
Since a boot manager usually supports multiple operating systems on one
computer and even one partition, it has to perform some preparatory actions
(create the boot context) before booting an operating system.
Operating system installation is a process during which its system folders are
created, system files are copied and boot sector is created. These are the
signs that allow Acronis OS Selector to automatically detect the newly
installed operating systems.
Operation system upgrade. Many operating systems may be upgraded. In this
case system files may change. Unlike other boot managers, Acronis OS
Selector performs correctly in most cases when an operating system is
upgraded.
Partition. An independent area on a hard disk where a file system can be
located. A partition can be either primary or logical, depending on its position
in the partition structure. One of the primary partitions of a hard disk may be
active. A partition has the following attributes: type, beginning and size.
Besides, some partition managing software and boot managers allow hiding
partitions. Information about partitions is stored in the partition table.
134 Appendix F. : Glossary
