While phishing and spear phishing attacks are similar, there are many key differences to be aware of. A phishing campaign is very broad and automated, think 'spray and pray'. It doesn't take a lot of skill to execute a massive phishing campaign. Most phishing attempts are after things like credit card data, usernames and passwords, etc. and are usually a one-and-done attack. .
On the other hand, spear phishing is highly targeted, going after a specific employee, company, or individuals within that company. This approach requires advanced hacking techniques and a great amount of research on their targets. Spear phishers are after more valuable data like confidential information, business secrets, and things of that nature. That is why a more targeted approach is required; they find out who has the information they seek and go after that particular person. A spear phishing email is really just the beginning of the attack as the bad guys attempt to get access to the larger network.