Glossary

What Is SEO?

SEO (Search Engine Optimization) is the practice of improving a website's visibility in organic (unpaid) search engine results. When someone searches for a service or topic related to your business, SEO is what determines whether your website appears on page one of results — or page ten.

How Search Engines Work (Simply)

Search engines (Google, Bing) use automated programs called crawlers to discover and index web pages. They then rank pages based on hundreds of signals, grouped into three main categories:

  1. Technical quality — can crawlers find, access, and understand your pages? (page speed, mobile-friendliness, URL structure, structured data)
  2. Content relevance — does your content actually answer the search query? (keywords, depth, accuracy, freshness)
  3. Authority and trust — do other reputable sites link to yours? (backlinks, brand signals)

SEO work addresses all three.

The Three Types of SEO Work

Technical SEO: Ensures search engines can crawl and index your site correctly. Covers site speed, Core Web Vitals, XML sitemaps, structured data (schema markup), canonical tags, mobile optimization.

On-page / content SEO: Optimizing individual pages for relevant search queries. Covers keyword research, title tags, meta descriptions, heading structure, internal linking, content depth and quality.

Off-page SEO / link building: Acquiring links from other websites pointing to yours. Backlinks from authoritative sites signal trust to search engines. This is the most expensive and time-consuming component.

SEO Cost by Type

SEO ActivityDIY CostFreelance/Agency Cost
Technical auditTime + free tools$500–$5,000 one-time
On-page optimization (per page)Time$100–$500/page
Monthly SEO retainer (small biz)Time$300–$2,000/mo
Monthly retainer (competitive)Not realistic$2,000–$10,000/mo
Link buildingDifficult DIY$100–$1,000+/link
SEO tools (Ahrefs/Semrush)$0 (free tier tools)$100–$450/month

See our full SEO Cost guide for a detailed breakdown.

SEO vs Paid Advertising

SEOPaid Search (Google Ads)
Time to results3–12 monthsImmediate
Cost structureTime/retainerPay per click
Traffic stops if you stopNoYes
Best forLong-term brand/trafficImmediate leads, time-sensitive campaigns
ROI horizonLong-termShort to medium-term

For most businesses, the right answer is both — paid search for immediate leads, SEO for long-term traffic that does not require per-click spending.

Free SEO Tools

  • Google Search Console — performance data, indexing status, Core Web Vitals (essential, free)
  • Google Analytics — traffic sources, user behavior (free)
  • Screaming Frog — technical site crawl (free up to 500 URLs)
  • Google PageSpeed Insights — performance analysis (free)
  • Ubersuggest — keyword research (free tier)