What is bad baclinks?

1. Poor site link means poor PA and DA sites link.
2. Irrelevant link from your theme
3. Hidden Link

Links from low quality, spammy and not so trusted sites.

Anything that links you from a bad link structure and comes from a pages that has lot of OBL to unwanted spammy websites

any link coming from a site.. having more then 4 spam score is consider a spam link

Any link that you can place yourself is likely to be a bad backlink, at worst, and relatively worthless, at best.

A bad backlink, as I understand it, is one that's been placed on a site but is completely irrelevant to the viewer of that site. In other words, spam. It's also known as black hat SEO and is totally frowned upon by Google so I'd avoid that.
Again, from what I understand, you can't get backlinks to your site yourself - you need to create shareable, keyword-rich, engaging content which encourages those in your niche to want to share as it appeals to their audience too. This is how backlinks work.
The only way to have a bad backlink is if you've paid someone dodgy to boost your SERP results, otherwise any share to your site is a good backlink.
That's my understanding of it so please let me know if anyone sees a bad backlink as something different to that?

Bad back links are those which are having low PA and DA. Also these links are considered as a spam which are PAID to increase your SERP result.

There is a whole bunch of methods that could be employed to discover bad links. Many of the methods can be implemented at an automatic tool and I am right now working on the algorithm. We keep you updated when it is available.
P.S. Meanwhile, I would not rely a lot on DA and PA

First backlinks being bad when google found you created link scheme or get caught create and spread useless & crappy content with your backlink on it. Second is Keyword distribution takes important roles of how bad your backlink is, diversity is key, dont forcing exact focus keyword to all your backlink profile, use LSI, Partial Match Anchor, generic anchortext and naked url combine into your campaign, i'm never using exact focus keyword more than 5% at my first tiered backlinks also if you plan to create 300 backlinks it would be wise if you make it a month project, don't you build all your backlink profile at couple days. Third is diversity again, but right now is about diversity of platform of your backlink came, it might be a factor of legitimate link building, more deverse it better, use web 2.0, social bookmarking sites, directory sites, forum signature, wiki sites and of course guest post or homepage from TLD wordpress sites for your first tiered, dont ever use automatic software like GSA or SEnuke, etc use automation linkbuilding software only for second or third tier. The point is according to my point of view there no such as backlink that wasting time or money, even unrich keyword domain name like number or dash like this "1232gawrqq-89dotcom" have their beneficial power for support your linkbuilding campaign as long they not leave a noob footprints like using same ip address, same style of template or same admin bio, also if you make PBN for living like me, you might want protect whois of all your PBN. How well websites you got for your backlink is matter but doesnt determine success of your campaign.
Sorry for long comment.

Important Things to Remember About Backlinks:
Not all backlinks are good
Too many backlinks can be problematic
Anchor text is important
Site quality and content is paramount
Spammy backlink tactics cause harm

I think If you create your website unrelated back links it's harmful for your website and low quality PA, DA , low high PR and spamming links is bad.
So you can avoid it for your website.
Thanks

Bad backlinks are ones that you've paid for and are unauthentic.

While it's perfectly OK to swap links with a friend or someone in your industry, if you're creating links with robots, spam sites or paying someone to share your content - that's a bad backlink.

You'll be penalised by Google and the short term gain just isn't worth it!

Links from minor search engine SERPS? Does it matter whether the search engine is a real one (i.e. actually provides a useful service, such as a niche SE) or a scraper masquerading as an SE? Of course allowing SERPS to be crawled is bad practice, but some of these are strong sites.
Site wide links (from your own sites, relevant sites, irrelevant sites, footer links from WP themes..)
Scrapers (and what if they are banned? If they are not in the SERPS does that mean there is no effect?)

Spam Anchortext
From 18+ web site, sandbox website..v.v
Many link out

Bad backlinks are:
1. links from a blog post that is not relevant to your niche
2. links from a website that is not relevant to your niche
3. from PBN sites
4. purchased links
5. links from bad quality website

On the other hand, quality badlinks are exactly opposite of the above. Building quality backlinks is by far the most effective way to get your page/site ranked high.

dave_hermansen leaves a good point that "Any link that you can place yourself is likely to be a bad backlink".

Check out Google's penguin algorithm, which gives you an overall context of bad backlinks. The Penguin algorithm focused on identifying sites that have undesirable(bad) link profiles and punishing them by lowering their rankings. Following are some examples of bad backlinks or likelihood to be a bad backlink:

1. article directories. Like content farm sites.
2. low-quality web directories.
3. overused of rich anchor text in links back to your site.
4. Links from countries where you don't market yourself.
5. sitewide links.
6. links sold by a link broker.
7. backlinks from an un-relevant site.
8. quality of neighboring backlinks.
9. links located outside of main content in a web page.
10. comment spam.

It is good to do a regular review of your own backlinks in a case of negative SEO happened to your website.

Bad backlinks means low quality backlink which topic google often mentioned intake their reviews.

Low-Quality Links: Low-quality links are links that come from collected sites, automated sites, spam sites, or even porn sites. Such links do far more harm than good. This is one reason you should be careful when buying backlinks.

Bad backlinks are comments that are auto-approved from sites that are not moderated, backlinks from sites with duplicate content and links from irrelevant websites and content.

Bad backlinks, or low-quality backlinks, is a topic that is often mentioned in the intake form of our reviews. Websites that have made the mistake of hiring some shady SEO company to buy bad backlinks for their website and have lost almost all their rankings often turn to us for a proper analysis of the drop.

Bad backlinks are those backlinks which are low quality, dead link or spam links. These are the examples of bad backlink

Low PA and DA backlink
paid Link
Link Exchange

Tips : before submit use Mozbar to check At least 20 DA and Low Spam Score

Links getting from low quality, spammy website is called low quality links. Whenever you will create a backlink then check very carefully site trust flow, domain authority, page authority etc.

Bad backlink
1. Poor site link means poor PA and DA sites link.
2. Irrelevant link from your theme
3. Hidden Link

No follow links.
Low DA of site
these links are consider as a bad links

A backlink is a clickable text on a website that links back to your site. A bad backlink is a link that comes from not so trusted website. The bad backlinks are easy to find. There are a lot of resources to finding out these spammy backlinks, which are both free and paid.

Bad backlinks, or low-quality backlinks, is a topic that is often mentioned in the intake form of our reviews. Websites that have made the mistake of hiring some shady SEO company to buy bad backlinks for their website and have lost almost all their rankings often turn to us for a proper analysis of the drop.

Thank you!

Happy to help you.

Broken Backlink, low DA site, Spammy are the bad backlinks. That will harmful for our targeted website.

Hentis, you'd be better off with looking for the definition of a good link. A good link is a link from a page that's related by content that's got a ton of backlinks from pages that are related by content.

Ahmed, no. Because you can get a score of 4 if your site is new or has few backlinks, even if those backlinks are the bestest of the bestest.

Dave, no. I have pages that have nothing but backlinks I placed that are ranking.

No, it's not how you get the backlink that matters, it's where the backlink's coming from that matters.

If you have a site about mortgage loans and the owner of a pron site decides to link to you from a subpage of a subpage that's got no backlinks because he/she/it/they like your content, the link is not a good link.

If you find a tool that gets you backlinks from other mortgage sites without the rel="nofollow" tag, you're going to shoot up in SERP's.

If you pay an insurance agent to get you a link from their home insurance to your FHA mortgage loan page, that's a good link, even if you paid for it. The only way that would be a bad link is if you told Google you paid for it in order to increase the ranking of your page. Are you going to tell Google that?

And, why is it okay to swap, you end up with the same thing if you pay them? Where's the difference from what Google sees point of view?

And no, you will not get penalized by Google if you do any of the things you say you shouldn't. You get penalized if you do them stoopidly.

Bad backlink simply means a low quality or spammy link from an untrustworthy site that will end up doing more harm to your website than good! Backlinking is an off page seo technique which is intended to improve the organic ranking of your site, increase the referral traffic and aid in faster indexing. A good backlink is one which:
1> Comes from a trusted source.
2> Falls in sync with the content of the page.
3> Doesnt look fishy or spammy.
4> Provides real value to the users.

Bad back-links are links that are spammed quickly and have no relevance to your content. Yes if you blast thousands of low quality links, it could hurt your rankings.

Broken Backlink, low DA site, Spammy are the bad backlinks. That will harmful for our targeted website