Help understanding Stored proc

hi guys! Can anybody please explain what does lines 4,6,8,13 and 26 does? Thanks in advance!

1 USE [PawnShoppeDB]
2 GO
3 /****** Object: StoredProcedure [dbo].[sp_Customer_AddCustomer] Script Date: 06/14/2007 16:50:07 ******/
4 SET ANSI_NULLS ON
5 GO
6 SET QUOTED_IDENTIFIER ON
7 GO
8 ALTER Procedure [dbo].[sp_Customer_AddCustomer]
9 @.Customer_FirstName varchar(50),
10 @.Customer_LastName varchar(50),
11 @.Customer_MiddleInitial varchar(5),
12 @.Customer_Address varchar(100),
13 @.Identity int output
14 AS
15 Begin
16 Declare @.DateCreated DateTime
17 Set @.DateCreated = getDate()
18
19 Insert into RCPS_Customer
20 Values (@.Customer_FirstName,
21 @.Customer_MiddleInitial,
22 @.Customer_LastName,
23 @.Customer_Address,
24 '0',@.DateCreated)
25
26 Set @.identity = Scope_identity()
27 EndLol.

Check books online (SQL Server help) for:
ANSI_NULLS
QUOTED_IDENTIFIER
Scope_identity()
output parameters

Alter proc replaces an existing proc with the same name with the code you posted. That'll be in the help files too.