Web services

Understood with the help of examples in the file /user/tests/externallib_test.php

User data is obtained through:
$searchparams = array(
array('key' => 'email', 'value' => 'myemail@mypochta.ru')
);
$result = core_user_external::get_users($searchparams);

Create:
$user = array(
'username' => loginmy,
'password' => 'pswd123',
'firstname' => 'Vvladimir',
'lastname' => 'Filippovv',
'middlename' => 'Vladimirovich',
'email' => 'loginmy@email.fake'
);
$result_insert = core_user_external::create_users(array($user));