Click-Through Rate(CTR) & SERP.
These are important terms in SEO as they are a translation of your website's performance in search engines. These metrics will tell you how good your site is doing with certain search terms in the Google Search Console. In short, after following this Joomla SEO guide your CTR and SERP should increase.
This metric will show you from the X amount of impressions(the number of times your sites was listed in a search query) users click on a link to your site, a higher CTR is always better and will tell you how good your content is by appealing users to click on the link to your site. A CTR of 2% or more for your entire site over it life spawn is good. CTR will increase when you rank higher in search results and when your rank no1 for a search query the average CTR is around 32%.
SERP stands for Search Engine Result Page and is the number of pages displayed when a user enters a search query in a search engine. Search engines, therefore, have to rank search results on relevancy by the use of algorithms. The higher your SERP listing the higher your CTR will be thus leading to more traffic. And for this reason, you want to optimize and increase your SERP ranking to reach a bigger audience. The main goal to have at least a SERP ranking of the 1st page in a search query relevant to your content. And then further optimize to try to reach the top listing on the first page.