apex:pageBlockButtons
apex:pageBlockButtons, this tag is used to define a set of buttons that are styled like standard Salesforce buttons. This tag must be a child component of on apex:pageBlock tag.
Example:
<apex:page standardController="Account">
    <apex:form >
        <apex:pageBlock title="Account Details">           
            <apex:pageBlockSection title="My Content Section" columns="2">
                <apex:inputField value="{!account.name}"/>
                <apex:inputField value="{!account.AccountNumber}"/>
                <apex:inputField value="{!account.type}"/>
                <apex:inputField value="{!account.accountNumber}"/>
            </apex:pageBlockSection>                       
            <apex:pageBlockButtons >
                <apex:commandButton action="{!save}" value="Save"/>
            </apex:pageBlockButtons>
        </apex:pageBlock>
    </apex:form>
</apex:page>
Result of the above visualforce page.
apex:pageBlockButtons attributes
dir, id, lang, location, onclick, ondblclick, onkeydown, onkeypress, onkeyup, onmousedown, onmousemove, onmouseout, onmouseover, onmouseup, rendered, style, styleClass, title.
To know more about apex:pageBlockButtons, refer this URL https://developer.salesforce.com/docs/atlas.en-us.pages.meta/pages/pages_compref_pageBlockButtons.htm

