type information in one column and second coloumn will know respo

[Mstotler]

I want to enter information (e.g. RM1) and the second column would
automatically input information that would be equivalent to it (e.g. Room 1).

Example:
Column 1: RM1
Column 2: Room 1

However; I want it to change as the information changes.

[GeorgeF]

The easy way is to know ahead of time the total range of Room numbers from which one could be entered in a given cell in column A. For example, if there are 7 or less (Rm1, Rm24C, Rm376, etc), then an IF statement in Col B will be a satisfactory application. That is, a formula in Col B could read
IF(A2="Rm1","Room 1",IF(A2=Rm24c","Room 24C",IF(A2="Rm376",'"Room 376",""))
If you have more than 7, and you know what they could be, then a VLOOKUP in Col B should be the ans. As a matter of fact, in a dynamic situation where new room numbers may infrequently come into your needs, then the VLOOKUP table could be easily expanded for future use.
i HOPE THIS IS OF HELP