"Literally" is used to emphasize that while it may say like you're speaking metaphorically, it really is in fact true. For example, "he is literally twice as tall as her" (his height actually is twice hers and it's not just said as an exaggeration). "Technically" on the other hand deemphasizes the actual situation. For example, "technically he's twice as tall as her, but for some reason he doesn't look very tall" (it shows that while true, it's somewhat surprising or isn't what's important).

Mona: How was the food in the cafeteria today? James: I don't know. I couldn't get in because there were a million people inside. Mona: Literally? James: Of course, not! ***** Mona: Can I come in? Store clerk: Well, it's 7:59 a.m., and technically speaking, no one can enter until 8:00 on the dot. But that's OK. Come in now. The manager is not here, so he won't see me letting you enter 60 seconds early.

Literally is supposed to mean that you're speaking the objective truth. It means that the very words you're saying is true. For instance, you might say that "the corn is literally as high as an elephant's eye" if there was an actual elephant standing in a cornfield with the corn reaching to its eye level. Technically emphasizes that while there is truth to what you're saying, there's other factors that make it untrue. For instance, technically there are only 46 states in the US because four of them call themselves commonwealths rather than states (but we generally consider them all states, so it's only a technicality). But it's important to know that nowadays, especially in the US at least, people use the word "literally" to mean the exact opposite of in order to exaggerate, usually for comic effect. So a person might say "I'm literally dying to hear what you're going to say next. No, really. If you don't continue in the next two seconds I will be lying on the floor without a heartbeat" when obviously they're not actually dying. The "misuse" of the word makes some people angry.