What is a tart and how to make shells?

What is a tart and how to make shells?
A tart is a baked dish consisting of a filling over a pastry base with an open top not covered with pastry. The pastry is usually shortcrust pastry; the filling may be sweet or savory, though modern tarts are usually fruit-based, sometimes with custard. 
Tartlet refers to a miniature tart. Examples of tarts include jam tarts, which may be different colours depending on the flavour of the jam used to fill them, and the Bakewell tart.
The words 'tart', 'flan', and 'pie' overlap, with no sharp distinctions, though 'pie' is the more common term in the United States. 
In French the word tarte can mean either pie or tart, as both are mainly the same with the exception of a pie usually covering the filling in pastry, while flans and tarts leave it open.
The Italian crostata, dating to at least the mid 1400's, has been described as a "rustic free-form version of an open fruit tart".
Early medieval tarts generally had meat fillings, but later ones were often based on fruit and custard.
The tarte Tatin is an upside-down tart in which the fruit (usually apples) are caramelized in butter and sugar before the tart is baked. The Bakewell tart is an English confection consisting of a shortcrust pastry with a layer of jam and a sponge filling with almonds. This tart consists of a shortcrust pastry shell, spread with jam or jelly and covered with a sponge-like filling enriched with ground almonds.
A butter tart is a type of small pastry tart and this tart consists of butter, sugar, syrup, and egg filled into a flaky pastry and baked until the filling is semi-solid with a crunchy top.
Custard tarts or flans patissier are a pastry consisting of an outer pastry crust filled with egg custard and baked.
The egg tart or egg custard tart (commonly romanized as dan tat) is a kind of custard tart pastry found in Portugal, England, Hong Kong and other Asian countries, which consists of an outer pastry crust that is filled with egg custard and baked.
A gypsy tart is a type of tart made with evaporated milk, muscovado sugar  could be brown sugar, and pastry.
It originates from the County of Kent in England and this tart is extremely sweet.
The Manchester tart is a traditional English baked tart, which consists of a shortcrust pastry shell, spread with raspberry jam, covered with a custard filling and topped with flakes of coconut and a Maraschino cherry.
A Neenish tart is a tart made with a pastry base and a filling consisting of sweet gelatine set cream, mock cream, or icing sugar paste, with dried icing on the top of the tart in two colors.
Treacle tart is a traditional English dessert. It is made using shortcrust pastry, with a thick filling made of golden syrup, also known as light treacle, breadcrumbs, and lemon juice. The tart is normally served hot or warm with a scoop of ordinary cream, ice cream or custard.
WHAT ARE TART SHELLS?
Does it mean the already prepared tart shells, which you can bake on a cookie sheet for about 10-15 minutes, or until golden brown, and then fill them with whatever you want. 
If you're filling them with something like a spinach/feta combo, just saute your onions and spinach and whatever else first, mix in some cheese and fill the baked cups. Or, you can make the filling ahead, and fill the cups up and then bake them. It works either way.
Then What does blind bake mean?
Blind baking is another term for prebaking, and it refers to a pie or tart crust that you partially or completely bake before it is filled. This is done in many cases to help keep the crust from becoming soggy from a wet fruit filling, or so that you have a cooked crust if you are filling the pie with something already cooked, such as a custard.
If you are prebaking the crust, it may only need another 5 minutes in the oven, until it is a very light brown. If you want to fully bake the crust, it may need 10 to 20 minutes more baking until it is done. You may also have to prick the bottom again if it gets uppity.
A tart shells recipe ...
TART SHELLS
http://www.cooks.com/rec/view/0,176,157163-245194,00.html
1 c. all-purpose flour
1 (3 oz.) pkg. cream cheese
1/4 c. plus 3 tbsp. butter, softened
Combine all ingredients in a medium bowl; stir until blended. Shape dough into 24 balls; chill. Place balls in ungreased miniature (1 3/4 inch) muffin pans, shaping each ball into a shell.
Yield: 2 dozen.