Success is generally defined in terms of achievement, fame, recognition, material possessions and wealth. In a word: outcome.
Significance, on the other hand, while less tangible, concerns the process. Significance is importance, meaning, essence, relevance and value. Success drives us by a desire for greater things; significance guides us by a desire for something greater than just what is tangible.
On the path of significance have a sense of 1 urgency, 2 whole of life and 3 defining what significance means.
The best is to build up both success and significance at the same time. However, one must not be prideful once successful. Need to be humble at all times. Also to realise that one can channel whatever one has gained in success to significance. It's all in the mindset whether one places success or significance to be the more important element in one's life and what legacy one wishes to leave behind.