6 month before I start my SEO carrier as a Off page Optimization, now I start work on on-opage optimization but i don't understand the difference between Title or meta tags. Please help me

Well, you probably need to learn about a few more tags than that so why not spend a half day studying HTML tags. There's tons of great, free, easy to understand resources available on the Internet, even some geared more towards a search engine optimization perspective.

The <title> tag is the title of the website. Search engines use this as the heading/link to the site in their results. They are also used as a factor in ranking web pages. Some search engines put more value on this than others.

Meta tags aren't used to such a degree. Google in the last few years have started using Meta description as the synopsis for webpage results, but maintains that it doesn't use it for ranking purposes. Meta's can also be used to tell a search engine not to index the page.

I don't keen on the difference between them but I know the weight difference them.
Title tag is the most important factor for on-page SEO while among all meta tags, only meta description tag is important.

both of them are html tags and really very useful for SEO purposes.

title tags is being used to set the title of any page and have great importance from seo point of view. There are many meta tags but meta description have more importance than others for search engines ...

They are both HTML tags... Title tag is for your title (what you see on top of the internet browser). Meta tag is for your keywords and description of your website. These two are used by search engine spiders to identify your website within their search engines.

Title tag and <h1> tag are the most important parts of the page (for se).

These tags are very helpful for the websites. Title mention about what is the page is all about. It should be select very carefully for getting ranking in search engine results because it is crawled first in hand by bots.