Human resource is the set if individuals who make up the workforce of an organization, business sector or economy. The professional discipline and business function that oversees an organization’s human resources is called human resource management (HRM, or simply HR).
There are several disciplines that are considered as part of the HRM, such as:

Benefits: which employers use to attract, recognize and retain workers.

Business Leadership & Strategy: process and activities used to formulate objectives, practices and policies, aimed at meeting organizational needs and opportunities, based off human capital issues.

Compensation: salary systems that are used to maintain the human resource value and productivity in the company.

Consulting: practice of delivering all aspects of human resource management as an external provider, focused on professional and business issues.

Diversity: supports business objectives acknowledging the differences and similarities that make employees unique.

Employee Relations: aims to maintain a positive, productive and cohesive work environment.

Ethics & Corporate Social Responsibility: focuses on organizational and personal values, and their expression in the business decision making and behavior.

Global HR: include all HRM activities around the globe and takes into considerations the differences between them.

Labor Relations: considers the elements of formal labor management relations.

Organizational & Employee Development: it is the organizational performance and the means by which it develops its human resources.

Staffing Manegement: strategies, tactics and processes for sourcing, recruiting, hiring and retaining the human resources needed to support the business objectives.