What is a postmeta table?

Question

WordPress

There is a layout that needs to be transferred to Wordpress, I am not a special specialist, but I have already created a theme and in order for the client to change the values ​​​​on the site I used the Advanced Custom Fields plugin.
This time the customer wrote a message that I did not fully understand, namely the part:
"It stores the value in postmeta table. but while fetching the value from database(postmeta table) no need to use this plugin's function, we will use Wordpress native function which is very simple and easy and powerful."
(Translation: "It stores the value in the postmeta table. but when getting the value from the database (postmeta table), you don't need to use the function of this plugin, we will use the built-in Wordpress function, which is very simple, easy and powerful.")
All correspondence in the pinned
My level of custom fields knowledge is to install the plugin and insert the shortcode into your code.
Help

Answer 1

Roughly speaking...
ACF stores its data, for example, in the wp_postmeta table as id, meta_key (field name or key), meta_value (field value), as well as the id of the entry to which the value is intended.
And to display it at the template level (at the PHP level), they use methods such as:
the_field() & get_field()
He says that instead of using the above methods, when displaying in the template, use the standard VI
method