Yes
The permissions helps to restrict/monitor the movement(accessing of resources) of the user in the domain.
File permissions in Linux are not represented in binary format, but rather octal format. The first digit represents owner permissions, second digit is group permissions, and the final one is permissions for everyone. Read permissions are assigned a 4, write permissions are assigned a 2, and execute permissions are assigned a 1. A 6 permission allows read and write (4+2).
TRUE
If you have read permissions on a file then you may read its contents.
When controlling access to data folders or files, permissions to these resources are assigned to individual user accounts or user groups.
User Group
A predefined set of permissions and rights assigned to user accounts is often called the terms of service or service terms. Although they are virtually everywhere they are largely ignored.
Privileges, in regards to computer science terms, are permissions granted by a system to allow certain data or files to be accessed or used. In UNIX, all files and data are assigned a set of permissions by the system. The files or data can be read, modified, and executed depending on the set of permissions assigned to the user.
TrueUse it to run a program using different permissions than those assigned to the currently logged-on user.A+ Guide to SoftwareChapter 5Page 256
permissions
Security groups Used with care, security groups provide an efficient way to assign access to resources on your network. Using security groups, you can: Assign user rights to security groups in Active Directory User rights are assigned to security groups to determine what members of that group can do within the scope of a domain (or forest). User rights are automatically assigned to some security groups at the time Active Directory is installed to help administrators define a person's administrative role in the domain. For example, a user who is added to the Backup Operators group in Active Directory has the ability to backup and restore files and directories located on each domain controller in the domain. This is possible because by default, the user rights Back up files and directories and Restore files and directories are automatically assigned to the Backup Operators group. Therefore, members of this group inherit the user rights assigned to that group. For more information about user rights, see User rights. For more information about the user rights assigned to security groups, see Default groups. You can assign user rights to security groups, using Group Policy, to help delegate specific tasks. You should always use discretion when assigning delegated tasks because an untrained user assigned too many rights on a security group can potentially cause significant harm to your network. For more information, see Delegating administration. For more information about assigning user rights to groups, see Assign user rights to a group in Active Directory. Assign permissions to security groups on resources Permissions should not be confused with user rights. Permissions are assigned to the security group on the shared resource. Permissions determine who can access the resource and the level of access, such as Full Control. Some permissions set on domain objects are automatically assigned to allow various levels of access to default security groups such as the Account Operators group or the Domain Admins group. For more information about permissions, see Access control in Active Directory. Security groups are listed in DACLs that define permissions on resources and objects. When assigning permissions for resources (file shares, printers, and so on), administrators should assign those permissions to a security group rather than to individual users. The permissions are assigned once to the group, instead of several times to each individual user. Each account added to a group receives the rights assigned to that group in Active Directory and the permissions defined for that group at the resource. Like distribution groups, security groups can also be used as an e-mail entity. Sending an e-mail message to the group sends the message to all the members of the group.
User accounts and groups are useful for determining who can access various resources on a network. There may be a large number of files and folders that certain individuals should be able to modify and which others should be able to read but not be allowed to change. Assigning permissions to individual users allows a network administrator to control who can read or modify certain files and folders. They can also be used to control access to other network resources, such as printers. Assigning individual permissions to large numbers of people where large numbers of network resources exist can be time consuming. This is where groups are useful. Rather than setting each individual's permissions for each network resource, the group is set permissions, then users are assigned as members of groups. In this way the group permissions can be modified as network resources change and users can be moved from one group to another (or be made members of multiple groups) which will save time and reduce mistakes.