DNA:

* Adenine (A)

* Guanine (G)

* Cytosine (C)

* Thymine (T)

RNA:

* Adenine (A)

* Guanine (G)

* Cytosine (C)

* Uracil (U)

Key Difference:

* DNA uses thymine (T), while RNA uses uracil (U). This is the primary difference between the two nucleic acids.

Base Pairing:

* DNA: Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C).

* RNA: Adenine (A) pairs with Uracil (U), and Guanine (G) pairs with Cytosine (C).