The base that is different in RNA compared to DNA is uracil (U).

In DNA, the four bases are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, thymine is replaced by uracil.

Here's a simple table to illustrate:

| Base | DNA | RNA |

|---|---|---|

| Adenine | A | A |

| Guanine | G | G |

| Cytosine | C | C |

| Thymine | T | Uracil (U) |