This is an answer to a question I got from a reader. The question had two things; firstly "How do I change the 'comments' label to something like 'reviews'?" and secondly "How can I change the label 'Posted by' to something different?"
There's something common about both of these questions. They both are Post Page labels (the word labels is used to mean string literals and not the labels used to categorize posts). Customizing these strings to something of your own is pretty simple. Just open the Blog widgets configuration dialog and change the strings as you like.
The illustration below is about how you can change the default comments label to "reactions".