Hi,

Diploma courses in engineering are generally offered after class 10th. They are more hands on and involve practical training as the end purpose of these courses is a job as a technician or the factory personnel who is involved with the machinery or process at the ground level. Most of these courses are offered by many engineering institutes and the admissions are restricted state to state. Diploma courses are three years in duration and if a student wants to complete an engineering degree after a diploma, they can opt for lateral entry which allows them them to start from the second year of engineering. Diploma courses also are specialised like Mechanical engineering, ECE, CS etc.

Degree courses are the ones that end up generally with a Bachelor's in Technology (B.Tech) or Bachelor's in engineering which is B.E. These are generally for students after class 12. Admissions are generally through entrance exams like JEE Main, JEE Advanced, BITSAT, VITEEE etc. Students who pass these courses are get to be engineers and start their careers at the basic management levels. Again engineering degree courses are offered discipline wise like mechanical, electrical, electronics and many more.

Certificate courses are enhancement courses specially to enhance the already existing qualifications. They are offered to students with a basic specified engineering qualification and are usually pursued by candidates who wish to add on to their existing qualifications.

Dear Latha

Diploma is 3 years course and it's similar to engineering and it's like you will lean the basics in engineering in your respective field like mechanical,  ece,  CSE etc..,  and also you don't have mathematics in diploma but in engineering you will get to know all subjects and the advanced topics too in the respective field what you've chosen. Engineering will be like make  you to choose what born for.
It will show you how everythings working etc..,
If you want more information,  comment here.
All the best.