Guidance and counseling is the process which helps the students to know their skills, interests, personality that will help students in further career selection.
Initially, I will explain about guidance and counseling.
Guidance is the process in which person able to know their ability, interest, a capacity that will help in the encounter of problems faced by them. Guidance is the process of a dynamic interpersonal relationship that is prepared to influence the person’s attitude and follow-up behavior.
According to McDonald, The objective of Guidance is to assist students and teachers in making available desirable qualifications and skills rather than achieving the goals of educational programs.
Counseling is the sharing of thoughts, reciprocal logic and guidance between groups or two. According to J. E. Smith, Counselling is the process in counselor has a broad discussion related to counsellee’s interest, planning, and adjustment.
So now the question is how guidance and counseling are related to school/college going students.
Students are very much focused on academic performances but they never assess themselves because they haven’t explored in Schools/colleges. They choose/plan their career not assessing self but with the influence of others expertise. 
It is quite obvious that if I am an Engineer, definitely I will suggest for engineering because I have expertise in this field only. Same is applicable for Doctor, Lawyer, designer etc. Here, students made mistakes during the selection of streams and career. Due to this reason, self-assessment is very important.
The earlier trend was not quite often because there were the limited scope and limited options but in recent days, scope and career options are quite broad that cannot be explored easily, then the trend of self-assessment came into existence and treated as very important. By self-assessment, students can be able to know about their Interest area, abilities, personalities, analytical level, and suited work styles. These factors play a significant role in stream and career selection.
Modern time, most of the students depressed related to a career decision. The simple and straight reason is lack of knowledge of current trends and developments, available streams, unable to know themselves. I have observed personally, students good in academics may be a topper in his/her respective classes but when the matter comes to a career decision, they are often failed to take the right decision.
Hence, guidance and counseling come into the existence and trend is increasing day by day. The counselors/experts have wide knowledge about current trends and developments, available streams and factors that have a major influence on career decision-making/planning. 
Counselors will be able to provide guidance and counseling to the students for encounters all problems related to career and update them related to current trends and developments, available streams. By guidance and counseling, students will be able to know about themselves and easily encounter the problems that they face in day to day life. 
This is most important for their bright and successful career. The identification of Interest, abilities, personality will help students to recognize their strengths and that is their strong zone, easier to sharpen. It is psychologically proven, the area, in which individuals are strong, find interest to explore that area and easy to build their career in the same field.
So, in the current trend, guidance and counseling are very much required for school/college going students to identify their strength, weakness and at the same time work on their strength and area of interest to do wonders in future