Advantages of having a full node
The main function of a node is to validate, if you have your own node you do not have to start trusting a third party.
The fact of having our own node and connecting the wallet to it assumes that communication with the Bitcoin network always starts from our full node and the validations on the transactions we carry out will be executed in the first instance by our node and will subsequently be propagated to the rest of nodes. We do not need to trust another node initially.
In a complete synchronized node you will find all the transaction history and you do not need another to verify the Bitcoin consensus rules, in addition you can also make all the queries you want about any transaction made in the past without having to resort to a web page or a third party node.
When a wallet communicates with an entire node, the IP addresses involved in the transactions are revealed, so a malicious node could end up identifying all the IP addresses stored in the wallet. If your wallet communicates with your node, you do not expose your IP address to a third party.
Here it must be remembered that Bitcoin is not anonymous but a pseudonym since all the transactions made are public and the addresses involved in it are shown, if you can associate those addresses with their owners you can have complete traceability of all movements and funds .
There are companies that are precisely in charge of performing chain analyzes on the Blockchain to associate addresses with real names.
If you are the owner of a complete node you can decide which Bitcoin update you run and which one you don’t, so you decide which evolutionaries you accept. This is the ultimate way to approve changes in Bitcoin. Light nodes, on the other hand, will always be at the mercy of what most complete nodes in their environment decide.
Protecting Bitcoin against a DDoS
A attack DDoS (Distributed Denial of Service) is a method used to interrupt access to a service from multiple machines. This is usually accomplished by overloading the destination with a massive amount of traffic, or by sending malicious requests that cause the target resource to malfunction or crash entirely.
The protection that Bitcoin has against these attacks is to have a large number of full nodes in its network so that although attackers can interrupt the service of one or multiple machines, there are thousands of other nodes more connected in the network, maintaining the service.