In general, testing is finding out how well something works. In terms of human beings, testing tells what level of knowledge or skill has been acquired. In computer hardware and software development, testing is used at key checkpoints in the overall process to determine whether objectives are being met. (source-google)
A physiological assessment gives detailed information on your current state of health, fitness, hormonal profile and so much more.
Let’s say, there is a problem with your vision. Will you just go to the pharmacy and buy some pills and pop them?. No. You take a consultation with an expert. In this case an Ophthalmologist .They will conduct a series of tests. They will also check your eyes for signs of an infection. The results of these tests will help them arrive at a diagnosis and put you on the correct treatment plan: spectacles ,eye exercises or just eye drops.
Similarly, a psychological or psychiatric assessment gives detailed information on your current and past subconscious and conscious patterns. It is also used to understand an individual’s functioning, behaviour, defence mechanisms, abilities, adaptive behaviour assessments, etc. to arrive at a diagnosis and treatment.
Psychological testing is used in all walks of life: like to measure an individual’s abilities, such as their aptitude in a particular field, cognitive functions like memory and spatial recognition, or even traits like introvertedness. Corporates use it for hiring candidates or role assignment, education system utilise it to assess a student’s ability to learn, and progress in the classroom or any stressors, legal system use to assess the mental health status of a person etc.
I mainly use drawing tests, handwriting analysis and psychological tests.