Question: There doesn't seem to be any difference between how [bioinformatics](https://biology.stackexchange.com/questions/tagged/bioinformatics "show questions tagged 'bioinformatics'") and [computational-biology](https://biology.stackexchange.com/questions/tagged/computational-biology "show questions tagged 'computational-biology'") are used, I would propose to merge those tags.

* Is there any argument against this?
* Which one should be the main tag?

Answer: 
I would argue that bioinformatics and computational-biology are actually different topics but in the context in which they are used here, it is more likely to be bioinformatics.

Bioinformatics would consists of most data analysis and data-mining. I would draw the line at biological simulations like folding@home and systems biology and define that as computational biology. However, none of the questions tagged so far fall under those categories.
I'm in favor of merging them. There is no single definition for either, nor a clear delineation between them. Compared to other areas of biology their overlap is so large that the tags should be merged. 

I'm less sure about the main tag, but I guess bioinformatics is more popular (and succinct).