Event or RbxScriptSignal are a major part of roblox scripting and what make roblox lua different from others version of lua. In this guide we will talk about the following things:
**What are RbxScriptSignal**
**How to use RbxScriptSignal**
**Tips and trick about using them**
In this guide you will see indicator such as the following :
The  will mean to go at the end of the article and to check what is the definition. Go at the end of the article to see an example of the meaning of the "Hello world"
RbxScriptSignal are a way for Instance to create event that will fire function when a event in the instance ocure.
You must know that in order to use RbxScriptSignal that it depend on the Instance class; You can't use the following example on a part but you can do it on a button. To know which event are available you have to use the roblox devhub and to know which event are available.
button = script.Parent button.Activated:Connect(function() print("Clicked!") end)
To sum up, different class have access to different RbxScriptSinal.
Here come the tutorial part: I will explain to you how you can script a part that change another part color when the other part touch the part.
Create a part in the workspace and insert a part. In the part, insert a script.
Go on the devhub, search for part and look out for the event called Touched.
To understand this documantation you need to understand the following thing Look at the screen shot. Here is the definition of what the parameter mean:
1: What you need to call the event with. 2: An parameter you will pass to the function that will be called when the event will be fired.
Create a part and a script into the part and define the parent of the script.
part = script.Parent
After defining your part you bind to the part the event. To do the following you define the instance with the event(RbxScriptSingal). It goes as follow:
Let's understand what the function in that snippet mean:
Part: The instance where we bind a event to Touched: The RbxScriptSignal(event) Connect: Establish the RbxScriptConnection to be called when the event is fired function(otherPart): Function is the function that will be called when the event and otherPart is the parameter that we pass on the function. Parameter depend on the function
Now what you will do is use the parameter of the function otherPart to change the color of the part that touched the part.
part = script.Parent part.Touched:Connect(function(otherPart) otherPart.BrickColor = BrickColor.random() end)
Congrat you made your first script using RbxScriptConnection and you learned how to use them.
Some instance share the same RbxScriptConnection. As example WedgePart and Part both use the Touched RbxScriptConnection
If you don't know which RbxScriptConnection are available for a instance go check out the roblox devhub for information on the RbxScriptConnection
 Hello, world: Sentence used to check if a compiler or a scripting language is working correctly.  Instance: The base class of all others class in roblox  Fired: Expression commonly used meaning triggering something  Event: Synonym for RbxScriptConnection