Random internal link?

i know internal link is good if you link to same topic/same category. but what if i create internal link to different category /different topic, does it good for my blog or is it better without internal link?
ps; (i am talking about general blog who have many topic like travel, business, news etc)

if it makes sense to link to different, unrelated category and / or you feel like your visitors reading an article in the business category - for example - would benefit from being taken to an article in the travel category then yes, you can link to that article. I don't think that linking from within content to a different category would make much sense, though.

So, linking from within article in category 1 to article in category 2 is fine as long as it's useful to the visitor and it's logical to link to article of category 2. But linking from article in category 1 to main page of category 2 is illogical (assuming that you've already linked to category 2 through your website's menu) and it's better not to do it.

My suggestion would be giving irrelevant interlinks can't make sense.
Giving properly related interlinks will make your visitors to stay in your website for more time.
If someone is reading about travel article if interlink directs them to business article they won't like it much.