 Hello there and welcome to video 7 in the Introduction to Latex series. This video is about the very important subject of environments in latex. In this video we're going to learn about environments in general and how their syntax works and then we're going to see some environments that change the formatting of text such as centering, flush left and flush right, and environments that change the size of text. So an environment is a block of a latex document that's being instructed to behave in some kind of way that is fundamentally different from the rest of the document. For example if I had a block of text that I wanted centered, I would need to have an environment for that. It will turn out that if we want to have a column of equations that are all aligned by their equal sign, we'll need an environment for that. And so environments show up very often in latex and they all have the same basic syntax. We have to have a way of telling latex when the environment is beginning and when it is ending. And we do that by typing slash end and then in curly braces give the name of the environment. And then enter in the stuff that we want in the environment and then tell it to end by typing slash end and then curly braces and then the name of the environment and then close the curly braces off. And so when you think about that, you've actually become very familiar with one basic kind of environment. And that environment is the document environment. We know all latex documents after the preamble is done start with begin document and end with end document. So document is one kind of environment. There are others. Let's take a look at a few and then the next few videos are going to focus in on even more. The center environment places text centered on the page. For example, if I wanted this sentence here to be centered, I would just put slash begin curly brace center close curly brace where I wanted the centering to start and then end center where I wanted to end. Another environment flush right is like center but it puts text all the way over to the right side of the page. Here it is in action. There's a similar environment called flush left. Environments are also how we get text to appear larger and smaller in the output of a latex document. For example, to make this sentence one notch larger than regular text, I use the environment large that has a small L lowercase L. This environment name like most other things in latex is case sensitive. If I use a capital L, I get text that is even larger than lowercase L large is. Likewise, to make text smaller, I use the small environment. So in general, to use an environment in latex, we find out which environment we need and what its name is and then we put slash begin name of environment where we wanted to start and slash end name of environment where we wanted to stop. There are many other environments in latex which you can find out about through your Google search. The next few videos are going to focus on some of the more important of these which are used for things such as producing auto numbered equations, aligned formulas, bulleted lists, and tables. Thanks for watching.