Restrictions can be applied at various levels: a government can apply them nationwide, an ISP can apply them to its clients, an employer to its personnel, a school to its teachers and/or students, a library to its patrons and/or staff, a parent to a child's computer or computer account or an individual to his or her own computer.
Limitations can be applied at various levels: a government can apply them across the country, an ISP can apply them to its customers, an employer to its employees, a school to its instructors and/or students, a library to its users and/or staff, a parent to their child's computer or computer account, or an individual to their own computer.