Friends at Ligonier are currently offering a concise teaching series on the subject by Dr. R.C. Sproul. Click here if you’re interested. Good stuff.
In the series Dr. Sproul turns the traditional TULIP acronym to something that is perhaps better defined though it is not so neatly packaged as the acronym. For instance:
T (Total Depravity) > Radical Corruption
U (Unconditional Election) > Sovereign Election
L (Limited Atonement) > Definite Atonement
I (Irresistible Grace) > Effectual Grace
P (Perseverance of the Saints) > Preservation of the Saints
For his rationale you have to watch the series. Again, good stuff.