The i10 index is a GS measure that counts for an author the number of publications that have at least 10 citations. The H-Index is a measure that counts your publications and citations in a descending order, and at the point when the number of publications matches the number of citations, this establishes your H-index. This last measure does not consider publications with many citations (at the top of the list).
H index : when number of citation equal number of paper cited, this is the H index. I.e if you had one paper cited once so your H index is 1. If you had two paper cited twice at least , your H index is 2, if you had 3 paper cited at least 3 times, so your H index is 3 and so on. I-10 index is the number of paper cited at least ten timed