You cannot submit your links to Google anymore as Google has stopped the manual submission due to spamming. However if your website is of high quality and implementing good SEO techniques, then it will be indexed by Google automatically.
In SEO, meta tags are the tags that helps in defining the content of the web page of a website. Types of meta tags are meta description, meta keywords, meta title, meta robots etc.
On-Page SEO tips which help in ranking the website are:
keyword density
submission of sitemap.xml
internal link
fast page loading speed
optimized content
In SEO, image optimization is defined as the optimization of images according to the rules of search engines such as image file size, alt tags/text etc.
Yes. Meta keywords and meta description are still effective to use in SEO as it help users and web crawlers to define the content of the web page of website.