Most Navy SEALs (about 2,000) are enlisted men who hold the rank of E-4 to E-9 (Petty Officer 3rd Class to Master Chief Petty Officer). They are led by roughly 500 SEAL Officers who hold the rank of O-1 to O-10 (Ensign to Admiral Chief of Naval Operations). There are also a few SEAL Warrant Officers (perhaps 30 or so) who rank as officers above the senior-most Enlisted but lower than a Commissioned Officer.
Like every military organization, there is a command structure, which requires having different ranks. The same is true of SF, Rangers, Delta, MARSOC, etc. There are no military organizations where everyone is the same rank.
If you instead meant “Do Navy SEALs have unique ranks?” then the answer is no. The SEALs are part of the Navy and use Navy ranks.
|E-4||Petty Officer Third Class||PO3||Noncommissioned Officer|
|E-5||Petty Officer Second Class||PO2||Noncommissioned Officer|
|E-6||Petty Officer First Class||PO1||Noncommissioned Officer|
|E-7||Chief Petty Officer||CPO||Senior Noncommissioned Officer|
|E-8||Senior Chief Petty Officer||SCPO||Senior Noncommissioned Officer|
|E-9||Master Chief Petty Officer||MCPO||Senior Noncommissioned Officer|
|O-2||Lieutenant Junior Grade||LTJG||Junior Officer|
|O-4||Lieutenant Commander||LCDR||Junior Officer|
|O-7||Rear Admiral Lower Half||RDML||Flag Officer|
|O-8||Rear Admiral||RADM||Flag Officer|
|O-9||Vice Admiral||VADM||Flag Officer|