Q:

How do I correctly check if text box is empty or not?

When I enter nothing in the text and click enter, it counts the length of the text as 1, which means there is something there. (Presumably a space), and entering an actual space in the text box increases the count by 1. I want to know how to check if the textbox is empty or not. If nobody enters anything in the textbox I want a way to see that.
from tkinter import *
from tkinter import ttk
from tkinter import messagebox

def submitted(*args): #Progressbar is set to be fully completed and states information recorded
    print(len(t.get("1.0", END)))
    if len(t.get("1.0", END))==1:
        messagebox.showinfo("Error", "No information entered in description.")

#Sets title and creates gui
root=Tk()

#Creates text widget
t = Text(root, width=20, height=10)
t.grid(column=0,row=1)

#Submitting calls submitted function to set progressbar to 100 and statemessage box has been completed
subbttn= ttk.Button(root, text="Submit", command=submitted)
subbttn.grid(column=1, row=1, sticky=(S, W, E))

A:

If you print out the content of the empty text box, you will see that there is a "\n", newline character. This is what is causing you to see that there is a length of 1 for an empty text box.
If you wanted to see if it was empty, you could check if there is just one new line. Or, like you are already doing, check if len(t.get("1.0", END) is one.
if t.get("1.0", END)=="\n":
instead of:
if len(t.get("1.0", END))==1:

