Because the tripod stands steady only if all three legs have a good ground. 

The same applies to any keyword and the three factors mentioned above:

• If the difficulty is OK and the keyword is relevant but it has no search volume, you’ll get no traffic because nobody uses the keyword.  
• If search volume and relevance are OK, but the difficulty is too high, you won’t rank for the keyword due to fierce competition.  
• If a keyword has a high search volume and low difficulty but the search intent doesn’t match, Google won’t show your page for the keyword.   

Keyword search volume refers to how many times a keyword is searched for in a search engine during a certain time frame (usually a month). 

The higher is the search volume of the keyword, the more visitors you’ll get if you rank for that keyword.  

Knowing the search volume helps you to: 

• Compare and prioritize the keyword topics 
• Estimate the traffic potential 
• See the topic popularity from the longer perspective  

Other things to consider

• The long-term trend
• Seasonality

Keyword difficulty is an SEO metric that estimates how difficult it is to rank for a keyword, based on the authority of the sites that already rank for that keyword. 

The higher the keyword difficulty, the harder it is to rank for that keyword.  

The metric on a scale of 1-10 takes into account the link profile strength of each page on the 1st SERP for the given keyword. So if there are many high-authority sites, it is more difficult to rank for the keyword. 

If, on the other hand, the result page contains sites with lower authority, it should be relatively easy to rank for the keyword. 

Search intent is the reason behind a searcher’s query. 

It helps us recognize whether the keyword and our content match together.  

Commonly recognized search intent types: 

• Navigational – the user is searching for a specific website/brand 
• Informational – the user is searching for general information 
• Transactional – the user wants to buy something online 
• Commercial – the user wants to do the research before purchase

Sometimes it’s hard to guess the search intent behind a keyword. 

Search engines deal with the same struggle. They don’t always know the search intent with 100% accuracy but they do their best to serve results that will most probably satisfy the user based on the large amount of data they have. 

The best way to find out the search intent behind a search phrase is to follow these steps: 

1. Look at the search results  
2. Scan the top 10 pages  
3. Identify the most common type of content