Kinds of Tenses, Types of Tenses, Use of Tenses in English Language

What is tense? What are the kinds of tenses?
Things can happen now, in the future or in the past. The tenses show the time of a verb's action or being. The verb ending is changed (conjugated) to show roughly what time it is referring to.
Time can be split into three periods The Present (what you are doing), The Past (what you did) and The Future (what you are going to do).
The tenses we use to show what time we are talking about are split into the Simple, Continuous and Perfect tenses.
    In English we use two tenses to talk about the present and six tenses to talk about the past. There are several ways to talk about the future some of which use the present tenses, these are:
Present:
Simple Present
Present Continuous
Past:
Simple Past
Past Continuous
Present Perfect Simple
Present Perfect Continuous
Past Perfect Simple
Past Perfect Continuous
Future:
Using the Simple Present
Using the Present Continuous
Using the Present Perfect Simple
Using the Present Perfect Continuous
Using going to
Using shall/will
Simple Tenses
The simple tenses are used to show permanent characteristics of people and events or what happens regularly, habitually or in a single completed action.
Continuous Tenses
The continuous tenses are used when talking about a particular point in time.
Perfect Tenses.
The perfect tenses are used when an action or situation in the present is linked to a moment in the past. It is often used to show things that have happened up to now but aren't finished yet or to emphasize that something happened but is not true anymore. When they end determines which of them you use. Perfect tenses are never used when we say when something happened i.e. yesterday, last year etc. but can be used when discussing the duration of something i.e. often, for, always, since etc.
References:
http://www.youtube.com/watch?v=U1fdTYAyRNg&feature=related
http://www.googleurdu.com/