The nursing process is a systematic method for planning and providing nursing care to patients. It involves five interrelated phases: assessment, diagnosis, planning, implementation, and evaluation. Assessment is the first phase and involves collecting subjective and objective data about the patient's health status through various techniques like inspection, palpation, percussion, and auscultation. The data is then organized, validated, and documented to form the patient's database which provides the basis for determining the patient's diagnoses, developing a care plan, and evaluating outcomes.