magento 2 create custom form in frontend and save form code example

Example 1: magento 2 backend custom form

<?xml version="1.0" encoding="UTF-8"?>
<form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
    <argument name="data" xsi:type="array">
        <item name="js_config" xsi:type="array">
            <item name="provider" xsi:type="string">employee_form.employee_form_data_source</item>
            <item name="deps" xsi:type="string">employee_form.employee_form_data_source</item>
        </item>
        <item name="label" xsi:type="string" translate="true">Employee Information</item>
        <item name="config" xsi:type="array">
            <item name="dataScope" xsi:type="string">data</item>
            <item name="namespace" xsi:type="string">employee_form</item>
        </item>
        <item name="template" xsi:type="string">templates/form/collapsible</item>
    </argument>
    <dataSource name="employee_form_data_source">
        <argument name="dataProvider" xsi:type="configurableObject">
            <argument name="class" xsi:type="string">Namespace\Modulename\Model\DataProvider</argument>
            <argument name="name" xsi:type="string">employee_form_data_source</argument>
            <argument name="primaryFieldName" xsi:type="string">id</argument>
            <argument name="requestFieldName" xsi:type="string">id</argument>
        </argument>
        <argument name="data" xsi:type="array">
            <item name="js_config" xsi:type="array">
                <item name="component" xsi:type="string">Magento_Ui/js/form/provider</item>
            </item>
        </argument>
    </dataSource>
    <fieldset name="employee_details">
        <argument name="data" xsi:type="array">
            <item name="config" xsi:type="array">
                <item name="collapsible" xsi:type="boolean">true</item>
                <item name="label" xsi:type="string" translate="true">Employee Details</item>
                <item name="sortOrder" xsi:type="number">20</item>
            </item>
        </argument>
        <field name="employee_id">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="dataType" xsi:type="string">text</item>
                    <item name="label" xsi:type="string" translate="true">Employee Id</item>
                    <item name="formElement" xsi:type="string">input</item>
                    <item name="source" xsi:type="string">employee</item>
                    <item name="dataScope" xsi:type="string">employee_id</item>
                </item>
            </argument>
        </field>
        <field name="employee_name">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="dataType" xsi:type="string">text</item>
                    <item name="label" xsi:type="string" translate="true">Employee Name</item>
                    <item name="formElement" xsi:type="string">input</item>
                    <item name="source" xsi:type="string">employee</item>
                    <item name="dataScope" xsi:type="string">employee_name</item>
                </item>
            </argument>
        </field>
        <field name="employee_salary">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="dataType" xsi:type="string">text</item>
                    <item name="label" xsi:type="string" translate="true">Employee Salary</item>
                    <item name="formElement" xsi:type="string">input</item>
                    <item name="source" xsi:type="string">employee</item>
                    <item name="dataScope" xsi:type="string">employee_salary</item>
                </item>
            </argument>
        </field>
        <field name="employee_address">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="dataType" xsi:type="string">text</item>
                    <item name="label" xsi:type="string" translate="true">Employee Address</item>
                    <item name="formElement" xsi:type="string">textarea</item>
                    <item name="source" xsi:type="string">employee</item>
                    <item name="dataScope" xsi:type="string">employee_address</item>
                </item>
            </argument>
        </field>
    </fieldset>
</form>

Example 2: magento 2 backend custom form

<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<update handle="styles"/>
<body>
    <referenceContainer name="content">
        <uiComponent name="employee_form"/>
    </referenceContainer>
</body>
</page>