Understanding the 3 basic types of SEO services

1. Code and server optimization (On-page SEO)

Also known as “technical SEO” I avoid this term because it is such a fundamental part from SEO that I cannot place it in a separate category, however it does require specific skills and a more than basic knowledge mostly in front-end development (HTML, CSS, JS, Ajax etc) and even some cases server-side knowledge (server-side rendering, PHP, regex, OOP etc).
For the non-coder two websites can seem the same and also for some coders 2 websites could look the same, but for the trained SEO professional (and also for search engines) two websites that seems from the outside identical could look very different and rank accordingly.

2. Content optimization (On-page SEO)

A very general rule of thumb is that more “quality content” that you publish more rankings and traffic your website can get. the term “quality content” is not a trivial term and needs a deeper understanding of the types of content, the types of user queries and query intent.

3. Link building (Offpage SEO)

If you’d stick a gun to my head and tell me to define SEO in two words I would have to say “Content and links”, obviously it is much more complicated than that, however, these are the two top ranking factors that can make a difference for ranking any website. Think of a link as a recommendation and a website that has many links from external websites means (and again this is very generally speaking) that it has more recommendations, hence higher page rank.
As part of the SEO strategy SEO’s try to gain links to improve rankings. It is important to mention that un-natural links are contradicting to Google’s SEO guidelines [https://support.google.com/webmasters/answer/7451184?hl=en] and technically considered as “Black Hat” SEO. However, in most competitive niches, it is nearly impossible to get top rankings without influencing link generation in some sort of way.

Additional SEO services:

ORM (Online reputation management)

This service usually requires advanced SEO understanding and capabilities, the aim is to outrank or remove negative results when searching a name of a person or a business

Social media optimization for Google SERP

This service usually happens only with reasonable SMM campaign management, but sometimes there are some discrepancies between the accounts and websites and Google sometimes is having “hard time” to recognize the brand and all its social profiles.

Negative SEO

Negative SEO is a “Blackhat” technic and the only reason I mention this is because it exists, I do not recommend this method, not at the business level and not at the personal level, but I do believe it is important to be aware of it even if just to be able to detect if SEO competitor is trying to engage a negative SEO campaign on your websites.
The general idea in Negative SEO is that massive amount of exact anchor links from low-quality domains and “bad neighborhood” websites will eventually harm or penalize the competitor’s website and its SERP rankings will drop accordingly.

Local SEO

How to decide the correct SEO budget for your business

Figure out the ROI on the SEO efforts

ROI (Return On Investment) is the SEO industry is a real pain and really I prefer calling it “Potential ROI” and not just ROI because it’s not really possible to promise specific results in this world on uncertainty which is called SEO

In-house SEO Vs SEO agency

Final thoughts