 Hi, welcome to the module 2 of this course, Regular Expression for Beginners. My name is Krishanaj Rana. Okay, now you know what regular expressions are. In this module, we will take a look in more detail at the regular expressions basics in text we used when we will build our first regex and we will also learn some regex engine fundamentals. Well, this regular expression subject is little bit complicated and hard to digest and I don't want to give you the overdose of it. So for easiness of learners, I have divided this module into some parts. So this is the part 1 of module 2 and in this part, we will be going to learn about regular expression engine like how a regular expression engine works internally and what are the different types of regex engines available today and then we will start to understand the real basic concept of regular expression engine syntax and elements in detail such as matching characters, what are the character classes and wildcard etc. And for demo purpose, wherever possible, we will use either PDF multi-tool which you have already know in the previous module or some online regular expression tool. So let's get started.