Controller:

public with sharing class Sample
{
    public string selectedValue {get; set;}
    public List<SelectOption> industry {get; set;}
    
    public void getIndustry()
    {
        Schema.DescribeFieldResult industryDescription = Account.Industry.getDescribe();
        industry = new List<SelectOption>();
        
        for (Schema.Picklistentry pl : industryDescription.getPicklistValues())
        {
            industry.add(new SelectOption(pl.getValue(),pl.getLabel()));
        }
    }
    
    public void checkValue()
    {
        System.debug('Selected Industry Type - ' + selectedValue);
    }
}

Visualforce Page:

<apex:page controller="Sample" action="{!getIndustry}" sidebar="false" showHeader="false">
    <apex:form >
        <apex:pageblock>
            <apex:pageBlockSection columns="1" >
                <apex:outputLabel value="Industry Type" />
                <apex:selectList size="1" value="{!SelectedValue}" >
                    <apex:selectOptions value="{!industry}"/>
                    <apex:actionSupport event="onchange" action="{!checkValue}" />
                </apex:selectList>
            </apex:pageBlockSection>
        </apex:pageblock>
    </apex:form>
</apex:page>

Output: