Magento 2: -How to get product reviews, each review with a star

Try to use bellow code in your phtml file You should not use the ObjectManager directly!

<?php
$productId = 'your_product_id';
$objectManager = \Magento\Framework\App\ObjectManager::getInstance();
$reviewFactory = $objectManager->create('Magento\Review\Model\Review');
$product = $objectManager->create('Magento\Catalog\Model\Product')->load($productId);
$storeManager  = $objectManager->create('\Magento\Store\Model\StoreManagerInterface');
$storeId = $storeManager->getStore()->getStoreId();
$reviewFactory->getEntitySummary($product, $storeId);

$ratingSummary = $product->getRatingSummary()->getRatingSummary();
$reviewCount = $product->getRatingSummary()->getReviewsCount();
?>
<?php if($ratingSummary){ ?>
<div class="product-reviews-summary short">
    <div class="rating-summary">
        <div title="<?php echo (int)$ratingSummary; ?>%" class="rating-result">
            <span style="width:<?php echo (int)$ratingSummary; ?>%"><span><?php echo (int)$ratingSummary; ?>%</span></span>
        </div>
    </div>
    <div class="reviews-actions">
        <?php echo __('('.$reviewCount.') Reviews'); ?>
    </div>
</div>
<?php } ?>

I found one link that helps to get a collection of each review

    <?php 
    use Magento\Framework\App\Bootstrap;  
    require __DIR__ . '/app/bootstrap.php';  
    $bootstrap = Bootstrap::create(BP, $_SERVER);  
    $obj = $bootstrap->getObjectManager();  
    $state = $obj->get('Magento\Framework\App\State');  
    $state->setAreaCode('frontend');  

    $reviewId = 5; //custom review id.  
    $ratingCollection = $obj->get('Magento\Review\Model\ResourceModel\Rating\Option\Vote\Collection')
                       ->addRatingInfo()
                       ->addOptionInfo()
                       ->addRatingOptions()
                       ->addFieldToFilter('review_id',$reviewId);  
    print_r($ratingCollection->getData());