The probability of getting heads with both coins being tossed is 1/4. The probability of getting a heads on one coin is 50% (or 1/2) since there is only two possible outcomes, heads or tails. When you factor in two coins, you have to multiply the probabilities together, 1/2 x 1/2, which is how you get the answer of 1/4 or 25%. Another way to reinforce this is that there are 4 possible outcomes to the flips. You could get a heads-heads, tails-heads, heads-tails, or tails-tails. Getting the heads-heads result is 1 out of 4 or 1/4 (25%).
