can affect rankings

1. Link Farms
It is a group of websites that simply link to each other. Then search engines introduced a filter and now link farms value for SEO has only a negative consequence for your website position.
2. Paid Links
Paid links are all of these: helpful, useless and may hurt your rankings depending on how you use them. Personally, I never bought any links and I would not recommend doing so.
3. Unrelated Websites
These can bring your rankings down a bit. I suggest obtain links from the relevant sources. It is better to have one link from a relevant site than five links from ones as far from your website :)

Hello summerwilkins would suggest me how to find relevant sies ??

these links don't help.

This is good to have link on relevant sites but the landing page is more important that anything.

Relevant websites are those who are relevant to your niche. Definitely i agree that landing page have more link juice.

Even link wheel effects our site .. in a bad way.. if not done properly,,,!!

What would be the best way to use link wheel properly? Link may brought about disadvantages on the site?

These are all black hat seo techniques!

Stay away from these techniques and follow the ethical ways respected by search engines!

Links from link farms are considered as spam links so we should avoid link exchange with link farms.

Ya,  it's affect negative ranking: 1:Link Farms, 2:Paid Links, 3:Unrelated Websites and also 4: link exchange, 5:reciprocal links etc...

thanks for the info, I will avoid these techniques.

According to summerwilkins,we should avoid off-page seo and focus on on-page seo.
Am I right?

Want to get ranked, you have to link building to get your site traffic increase, but you should do some sort of blog to attract search for the unique things you want to get traffic to your site, of course you have to do some websites optimization, you need to do some link building to your site, for example, the class blog

You have to be careful while you are posting on any directory websites. In a short research, I have found many directories which are involve in farm-linking or spamming. It might affect your website adversely. Beware of those websites.

Yes, black hat techniques will affect SERP ranking

search in Google for your website niche,for example if you have wallpaper site so then search for wallpapers in Google and you will get lot of sites related your niche it is easy and simple method that i know about this hope it will help you ........yes i totally agree with you in first 2 points but i think  3rd one is not harmful and  you can use it for your website rankings .........

Link farms & paid links affect your websites ranking as these are the black hat techniques. Unrelated websites helps to get a low quality backlinks so always try to get backlinks from the niche websites. Because backlinks from the niche websites are considered as a quality backlinks

Yes, these 3 point are very important .
Thank you for sharing .

Yes, All are not good techniques and it will make harmful to your site. Google hate that kind of techniques.