Hello Jobin

UG means under graduate it can be degree of 3-4 years like Bsc,BA,Btech etc and PG means Post graduate, it is considered as masters degree and generally it is of 2 years.

For general medicine and surgery

You can go through this section of the website

https://www.careers360.com/general-medicine-and-surgery-course

Here you can get detailed explanation.

And

For all type of courses you can go through

This link

https://medicine-careers360-com.cdn.ampproject.org/v/s/medicine.careers360.com/articles/medical-degrees/amp?amp_js_v=a2&amp_gsa=1&usqp=mq331AQCKAE%3D#aoh=15747824121429&referrer=https%3A%2F%2Fwww.google.com&amp_tf=From%20%251%24s&ampshare=https%3A%2F%2Fmedicine.careers360.com%2Farticles%2Fmedical-degrees

I hope it helps.