HTTP Status code are the three digit code starts from 100 to 500, it is generated by the server which indicates the status of the webpage or a web element a user is seeking for.
Types of HTTP Status Codes
There are a many status codes, but in this tutorial we will focus on the most common status codes influences SEO.
302 : 302 status code refers to temporarily moved or redirect the page, but this is not a good practice as because it keeps the value of original page and hence google treats it as a duplicate url with duplicate content.
301: In other hand 301 status code means that the page is permanently moved and it tells the google crawler to forget the original page url so the google will start crawling redirected page, hence no duplicacy is found which is positive for your website health.
404: It is generally seen as 404 Page Not Found, this error implies that the webpage user is seeking for does not exist or could not be found on the server. This is basically the client side error means that the page is locomote or eliminate but the URl is not redirected if moved or changed if eliminated or the URL entered by the user is mistyped which is incorrect.
410: HTTP Status 410 means Gone in other words we can say that their is no redirection and any redirected address left. Such conditions are permanent removal of the page, hence it is clear that it is an optimal HTTP status code to permanently remove a URL from Google's index.
500: 500 error code comes when their is some software, coding or server issue on your website. Hence such issues put really bad impact on web page rank and it should be fixed as soon as possible.
503: This status code is applied when site is on maintenance and it insures the search engine that the website is on maintenance so the shutdown will be temporary and will be available very soon. Therefore the search engine will not penalize the website and crawl the temporary version till the maintenance is on.