Google Analytics' main job is really just generating the reports and statistics about your website, like how many people saw your website yesterday, what web browser they used, which pages were the most popular, etc. The only way it can know this stuff is if you put a "tag" on all of your pages. The tag is the javascript code on your pages that runs on the visitor's browser, which tells Google Analytics' servers that they are visiting the page right now.
There's no problem if you just want to put the tag in the master file of your website so it shows up on all of your pages. Google Analytics can use the "referrer" parameter to figure out which page the visitor is on and can do all the simple stuff like counting page views.
However, you may want to track how many people use a specific feature. Maybe you want to group certain pages together or count some similar but different URLs as being the same page. Now you need unique tags for all these different features and groups of pages so Google can identify which feature or type of page got used or visited. Now it's complicated! You have multiple tags, and you only want the tags to "fire" sometimes (e.g. don't fire unless they click this button or use this feature.)
Google Tag Manager makes it easier to manage this mess of tags by letting you define rules for when your tags should fire. It also lets you test your tags to make sure they go off when you load the right page or click a certain button. This is done by putting the Tag Manager's code on your website instead of the actual tags, and as Crayon's answer points out, the tag manager outputs the tags for you. This gives you another cool benefit: you can change your tags and the way they work without actually changing the source code of your website (which you may not be able to do because of slow-release cycles) -- instead you just change it from the Google Tag Manager website, and it will spit out different code on your pages dynamically when they're loaded in the visitor's browser.
Google Analytics' main job is really just generating the reports and statistics about your website, like how many people saw your website yesterday, what web browser they used, which pages were the most popular, etc. The only way it can know this stuff is if you put a "tag" on all of your pages. The tag is the javascript code on your pages that runs on the visitor's browser, which tells Google Analytics' servers that they are visiting the page right now.
There's no problem if you just want to put the tag in the master file of your website so it shows up on all of your pages. Google Analytics can use the "referrer" parameter to figure out which page the visitor is on and can do all the simple stuff like counting page views.
However, you may want to track how many people use a specific feature. Maybe you want to group certain pages together or count some similar but different URLs as being the same page. Now you need unique tags for all these different features and groups of pages so Google can identify which feature or type of page got used or visited. Now it's complicated! You have multiple tags, and you only want the tags to "fire" sometimes (e.g. don't fire unless they click this button or use this feature.)
Google Tag Manager makes it easier to manage this mess of tags by letting you define rules for when your tags should fire. It also lets you test your tags to make sure they go off when you load the right page or click a certain button. This is done by putting the Tag Manager's code on your website instead of the actual tags, and as Crayon's answer points out, the tag manager outputs the tags for you. This gives you another cool benefit: you can change your tags and the way they work without actually changing the source code of your website (which you may not be able to do because of slow-release cycles) -- instead you just change it from the Google Tag Manager website, and it will spit out different code on your pages dynamically when they're loaded in the visitor's browser.
GA is the analytics tool that provides reports about activity on your site. GTM is a tag manager that can output tags based on defined rules. So for example, you can either implement your GA code on your site directly, or you can implement the GTM code and use GTM to output the GA code.
The main benefit of GTM (or any tag manager worth anything) is that you can use it for multiple tags or code snippets or pretty much anything you want. Usually you implement a data layer and a set of rules, and then within the tag manager interface, put a new tag or code snippet under those rules, using stuff from the data layer. That way for example, if you use GA today and then tomorrow want to also implement a different analytics tool e.g. Adobe Analytics, you can just do it within the GTM interface following the same rules and data layer you setup already.
So IOW GTM is a container in which to output other stuff. GA is one of the "other stuff" you'd output.
Videos
Does Google Tag Manager replace Google Analytics?
Is Google Analytics part of Tag Manager?
Can you use GA4 without GTM?
I installed linkedin and twitter tags in google tag manager for all pages.
I don't know why I did that or why it's important.
Can someone explain it to me like I'm 5? Very grateful for any feedback.
Hugs
I'm setting up GA4 on a website and I haven't done this in a while. When I last did this, there were separate tags you could create in a container specific to GA4. Now, they have the sort of catch-all Google tag. When you are in Tag Manager creating a new tag, you get a list of tag options to choose from. In the main list, there is a Google Analytics subsection, but there is also just a "Google Tag" option below it in the main list. However, when you go into the Google Analytics subsection, it has what appears to be the same "Google Tag" (and the GA4 Events tag). My understanding is the the Google Tag itself collects most of the basic events for analytics, but my question is this: Assuming that I don't need to set up any special events, do I need to create a tag using the "Google Tag" under the Google Analytics section AND create a tag using the "Google Tag" option on the main list? Or is that just the same thing?
Hopefully I explained that well enough. I was following this guide and it just shows you how to set up the Google tag with Tag Manager. As you can see, he selects the Google tag present in the main list. So I'm just wondering if I need to do anything more than that to get basic analytics because it seems as though there is no difference between that tag and the one in the "Google Analytics" section (excluding the events tag).
you can leave the global site tag tracking code snippet on your site, just do not also configure tags for GA pageview tracking within GTM.
If it were me, I would remove the global site tag tracking code snippet and configure tags for GA tracking within the google tag manager container.
Bit of extra information:
Both Tag Manager and gtag.js perform similar functions:
Tag Manager is a tag management system that allows you to quickly and easily update tags on your website or mobile app from a web interface.
gtag.js is the JavaScript framework that is used to add Google tags directly to web pages.
https://support.google.com/tagmanager/answer/7582054?hl=en
You need to add your Google Tag Manager code in your website.
Then, you have two options:
Leave it, don't do anything else. Your Google Analytics code will remain as it is and FB Pixel will be added via Google Tag Manager.
Alternatively, you can remove the code for Google Analytics from your website and add a tag in Google Tag Manager https://support.google.com/tagmanager/answer/6107124?hl=en (Recommended option for efficiency)
Do not mistake Google Tag Manager with the Global site tag you used to add Google Analytics, they are different things: https://developers.google.com/gtagjs