in this part of the course we're going to discuss the difference between storing data in excel and storing it in access in excel generally you store the data in a flat database what i mean by that is that you've got one table that contains all of the information here's an example which you'll find in the files that i've provided for you it's the camera product list excel file and you've got your list of products here essentially 20 products and you've got all the product information here but you've also got for every row all the supplier information so we need to know for each product who our supplier is the problem with storing data in this ways is extremely inefficient and i'll give you some examples of why that is the case for example our products here obviously use different suppliers but there'll be more than one product that uses the same supplier for example catering supplies to you is used many times you can see in this list whenever i create a product in this database that uses catering supplies to you i have to write all this information out each time it's the same information but it's got to be entered into the database each time i create a product what's more if i need to make a change to the supply details catering supplies to you maybe it's the contact name or email address or something like that i've got to make that change to each instance of the supplier in my database and if you've got thousands of thousands of products you can imagine how time-consuming that could be hopefully you can see that this is not an efficient way to store your data now i'm going to show you the same data but in an access database i'm just going to move to access and this file is also available to you and basically we've got the same information here we've got the products table which contains the product information but it doesn't contain the supplier information and we've got a separate table that contains the supplier information now what we do in access is we split the data up into separate tables so all the related information is together and then we join the information back together via relationship and we'll go into this in more detail later on through the course but just for now i want you to get the concept that we're splitting the information up into separate tables and then we're relating the information back together using field relationships i'll just show you the relationship view here what we're actually doing in this database is we're linking fields between the two tables i've got the product information all here and the supplier information here well what i've got is this little field here called supply code that links to the information in the supplier table that means i only need to store each supplier information once within the database but i can refer to it many times in the product table now what that creates for you is a much more efficient way of storing the data but for example if i go to the suppliers table and i expand catering supplies to you here you'll see that all the products that relate to that particular supplier are listed underneath that supplier and i can do the same for direct baking supplies those are all the products that they supply so i only need to store the information once for each supplier and relate all the products to that supplier via field relationships that's what we're hoping to achieve during this course moving from a flat database to a relational database now there are other advantages to using access over excel and what i've done here is given you a little link that you can click on and that'll take you to a microsoft page which will explain all the advantages i'm not going to go into them in a great amount of detail here it's something you can read but it will tell you for example when to use access and when to use excel it goes into some detail on that okay that's all that's going to be covered in this part of the course have a look at those files make sure you can kind of understand the concept here the difference between a flat database and a relational database