Celerons are entry-level CPUs designed for very cheap laptops. They are slow, not future-proofed, and are generally only good for basic productivity tasks like Word document creation and light web browsing. An i3 CPU is far more powerful than a Celeron. Note that even if you only use your laptop for simple tasks, it would be wise to get a better processor, because this ensures that your laptop will be competent for a longer period of time. Minimum requirements for software do rise over time as hardware becomes more powerful.
I've looked at the two models you're choosing from, and it appears that the HP with an i3 is a better choice.