Comparison between benefits of publishing a paper at a conference and a journal My friends submit their papers at different conferences. They visit to another university or institute in India or abroad to present their work at a gathering of researchers which is formally called conference. To celebrate it they share snapshots in Facebook, discuss their experience of a foreign trip, grand dinners, gossiping with new friends, so on and so forth.

To continue a good piece of research work, one face a lot of hardness and difficulties. Hence, one may expect maximum benefit from it. My question is how beneficial submitting a paper at highly reputed journal rather than a highly reputed conference academically? Which one is better?

Please compare between the benefit of a journal and a conference publication from different perspective. Note that, I am at the very beginning of my research career in Mathematics.
This depends on your field. In computer science, publishing at the best conferences is worth more on your CV than publishing in journals. In most other fields, journal publications (even in mediocre journals as long as they are properly peer-reviewed) are worth much more on your CV than conference papers at even the best peer-reviewed conferences. 

Assuming that you are not in computer science or a field that shares its unusual norms, a good journal paper will be:


A more meaningful line on your CV;
More likely to be widely cited (or cited at all);
More likely to be thoroughly peer-reviewed, which may help to improve the paper (peer-review at many conferences is cursory or non-existent);
More likely to be indexed by Web of Science and Scopus so that it can be easily found and so that your citations can be counted;
More likely to be assigned a permanent DOI and permanent "home" on the web and in library collections.


Publishing via conferences does have advantages, though:


The publication process is usually faster, which can be particularly
important in fast-moving fields;
Conference papers are (in many if not most fields) much easier to get accepted for publication than papers in good journals;
Conference papers can be a good way to get early feedback on - or publicity for - work in progress;
Some conferences are closely associated with scholarly societies and their journals, and conference papers are sometimes considered
drafts of potential journal papers (authors of the best conference
papers may be invited to submit extended versions to a journal, for
instance);
Some treat conference papers (or at least, conference seminars) as a way to get publicity for already-published journal papers;
Attending conferences is a great way to build connections within your field, learn about the latest work of other groups, and meet
people who may be interested in your results or in working with you
in future. They can also be great fun.