Technical corrections. This is the feedback that mentions specific mechanical problems with your work. Inadvertent change in point of view or tense, typos, punctuation issues, and other types of spelling or grammatical errors. In general, I think these are generally a good idea to address, as long as they're correcting actual errors and not stylistic choices. After all, your work only gets stronger when you address technical errors that could hinder readability.
Technical suggestions. There are a whole host of technical issues that people are largely undecided upon and argue over. For example, people differ in their opinion of whether you can begin a sentence with a conjunction ("and," "but," "so," etc.) so a review telling you to correct that issue when you fully intended to start a sentence that way is not the same thing as fixing a missing comma between clauses in a sentence. In general, technical suggestions are always worth considering, but it will ultimately be a matter of whether you stylistically want to have it one way or the other. Here is a short (and by no means exhaustive) list of grammar "don'ts" that are actually okay in certain stylistic situations:
Using passive voice.
Beginning a sentence with a conjunction ("and," "but," "so," etc.)
Ending a sentence with a preposition ("of," "up," "for," etc.)
Splitting infinitives ("to boldly go" rather than "to go," "to strongly disagree" rather than "to disagree," etc.)
Double negatives (can sometimes be used to avoid speaking plainly, e.g., "He's not unattractive.")
Using "they" or "them" to describe an individual (English has no gender-neutral pronoun to use)
Paragraphs must contain at least three sentences (one-sentence paragraphs are an acceptable stylistic choice)
Contractions are not acceptable in proper/formal writing (Spelling out, "Can't you help?" would require you to write "Can you not help?", putting the subject between the individual components since "Cannot you help?" doesn't make sense.)
With each of these issues, for every person who says, "No, never do that!" you can probably find someone who says, "Yes, that's fine!" The important thing is to consider the suggestion, then decide for yourself whether it's better one way or the other. Is spelling out a word rather than using a contraction a better choice there? Does the passive voice make for a less effective sentence than one written in active voice? Is the split infinitive adding an unnecessary adverb or does it serve a purpose? All of these decisions are subjective ones; you're not required to address them unless you're either correcting a clear error or stylistically prefer the suggestion someone made to your own way of doing it.
Creative suggestions. This is a huge category because the suggestions can include differences of opinion on anything from concept to story to character development to structure to dialogue to formatting. The most important thing to remember here is that you should be developing a personal style as a writer. Some writers are very lush in their description while others are sparse. Some are heavy with the metaphors and similes while others prefer to speak plainly. Some like to use a thesaurus to its full extent and talk in terms of crimsons and burgundies and scarlets while others will tend to just call it "red." These are subjective choices we make as writers and there is even less certainty here than there are for technical suggestions. Some of the creative choices that people may comment upon include (but again aren't by any means limited to):
Word choice
Structure of sentences, paragraphs, and/or chapters
Amount and/or type of sensory description/imagery included
Literal vs. metaphorical description
Choice of narration (point of view, tense, etc.)
Use and quantity of dialogue
Use of literary devices (alliteration, onomatopoeia, hyperbole, symbolism, etc.)
Pacing, amount of action, etc.
These can be the most difficult aspects to consider because there is no right answer, and there aren't any clearly defined options, like with technical suggestions. With a technical suggestion, you either like the way a sentence sounds with a preposition at the end of it, or you don't. One way works better for you than another, and it's simply a matter of choosing between defined options. With creative suggestions, though, it can be difficult to weigh the desirability of a particular word choice against all the other possible synonyms out there, and you can debate the merits of first person versus third person perspective from now until the end of time. At the end of the day, though, it's you - the author - who have to make a decision and stick with it. Reviewers may provide their thoughts or preferences that you can take into consideration... but if a reviewer says they wanted more sensory detail (smells, tastes, sounds, etc.) and you're a writer who primarily focus on visual description, you're not wrong just because someone else prefers it another way. Even if they gave you a low rating or you didn't place in a contest because of it, that creative choice is still your decision and one you should stand by if you believe in it.
In my opinion, reviewers should be very careful with these kinds of creative suggestions too. A review should be about what works and doesn't work for you as it's written... not an opportunity to tell them how
you would write their story. There's nothing wrong with an offered suggestion or example of what you're talking about here and there, but make sure you're discussing how to improve the story that they've written rather than how to make it the story you'd have written.