Short Answer: The Google Keyword Planner tool will show you more Search Volume than it should for SEO purposes. Meaning that it will show you in how many Search Queries it can display your Ad. It does not show you how many people search for that keyword on Google.
Long Answer: In the past even good SEO experts have used the old Keyword Research tool from Google Adwords. Make sure that you understand that tool is no longer existent. They have taken it down and replaced it with the Keyword Planner tool. This new tool is 100% designed to help search advertisers, not search engine optimization professionals.
It’s for buying ads, not for deciding how to serve smart organic search listings.
The small thing you could use from it is the part where it suggests keywords, but don’t look at any of the data. None of that data will help you. Here I would recommend tools like the Squirrly Keyword Research Tool (which shows high quantities of useful long-tail keywords) or Keywordtool.io or Ubersuggest.
Squirrly has very advanced algorithms and data sources which have been created for the specific purpose of serving organic content that matches the user’s intent, when the user searches on Google.
In Squirrly, the search volume is shown for: “keyword” (exact match), NOT for keyword (broad). The keyword planner from Google is not to be used for SEO purposes because it offers keyword info to be used in search advertising, not in organic. Therefore, they show volumes for broad searches and sometimes even similar, because those are SERPs where they could also show your ad, even though it’s not 100% your exact match keyword.