The expanded form of a number is written out in such a way that you would be able to see the math value of individual digits.
The number 25,049 which reads "twenty five thousand and forty nine," can be written in expanded form as follows;
2 x 10000 = 20,000
5 x 1000 = 5,000
0 x 100 = 0
4 x 10 = 40
9 x 1 = 9
So, as you can see the expanded form shows that the digit 2 (for example) in this number has a value of 20,000.
The place value chart groups the number in threes starting from the right to the left. That is, you count three numbers from the end (right hand side) insert a coma, and take the next three set of digits and so on. You can now tell the value of each digit by starting from the left (the begining) to the right (the end). Usually starting with billions, the chart now tells you the value of each digit. So in this question, you can read from left to right and by using the expanded form, you can tell the value of the 2, the 5, and so on till the last digit.
They are alike because the expanded form helps you determine the actual value of each digit without mistake, and the place value also tells you which number carries what value.
They are different because an expanded form gives you details of how each number gets its place value, while the place value chart simply tells you the value of each digit simply by arranging and inserting comas.