I've created an outgoing transaction using the GUI desktop app. I confirm the amount. Then the fees. After this step, there is a "change" value displayed. I have rejected the transaction since i do not know how to make sure the value displayed is correct.
In that context, what does "change" mean?
Change is basically the amount of XMR that gets sent back to your wallet. Let's say you received an output of 10 XMR from an exchange, a service, or someone who you traded with. Subsequently, if you make a transaction, of 5 XMR, the Monero GUI software will use that 10 XMR output as input. Thus, you have a transaction with 1 input (10 XMR) and 2 outputs, i.e., a 5 XMR output (minus the fee) that goes back as change to you (the sender) and a 5 XMR output that goes to the recipient.
If you have trouble grasping the concept of inputs and outputs, think of them like bills. Let's say you received $20 from your grandma for your birthday. This $20 is the output you initially receive. Subsequently, you use that $20 to buy some groceries worth $10. You hand the cashier your $20 bill and will get $10 back from him/her. In this "transaction" the $20 bill is used as input, the $10 you have to pay for groceries is the output that goes to the recipient, and the $10 change you get back is the output that is sent back as change to the sender.
