What is the difference between internship, inplant training and industrial visit?

Okay, interesting question.

Internship:

Internship is meant to expose the students to the work that happens in the industry. The course curriculum typically focuses on the theory part and students must understand how to implement the knowledge they've acquired.

In internship, the corporates take a few candidates and let me them work on existing, ongoing projects. They typically interact with the existing employees of the company who are working on the project and acquire technical and non-technical knowledge.

It's similar to 'on the job' training that gives the students the experience they should have before joining the workforce as employees. The benefits are two folds -

Students get accustomed to the industry they will eventually be joining
Employers can spot the bright students who are fit for the company culture

I've known several students who got picked up by the companies where they were interns for 2-3 months. I strongly recommend at least 3-6 months of internship.

Inplant Training:

It's typically a short-duration training program for the students. It's still a form of training but it happens actually on the site. Knowledge transfer happens between the existing employees of the company and the students seeking inplant training on the premises.

In case of engineering, inplant training is essential. Students get to understand how different levels of management work and what roles they've to execute at each level. It also exposes them to real-world problems and solutions.

For example, several electrical and mechanical engineering students undergo inplant training at Thermal or Gas power stations where they understand different kinds of jobs. Of course, they are supervised by experienced professionals all the time; but the knowledge obtained is very precious.

Industrial Visit:

Industrial visit typically lasts for a day or at max, two. It's only meant to 'introduce' the students to the industry and its functions. No detailed KT (knowledge transfer) happens and typically the professors in-charge will be responsible for KT.

Industrial visits are okay and necessary - but think multiple times before writing about it in the resume.

I've seen several students write about their industrial visit - but have no clue about the related questions asked during interview.

What I recommend for every student is a long-term internship because that's what prepares them for the industry. I hope this helps. If you have further questions, ask them below.