The two words describe two different things.
The rate type says who sets the rate: 'fixed' means the rates are written into the contract from day one; 'variable' means a reference rate (such as one of the Central Bank's rates) plus or minus the bank's margin, which changes when the reference changes.
The rate schedule says how the rate moves over the term: 'stepped' or 'declining' means year 1 has the highest rate and later years lower ones.
So a 'fixed stepped' certificate has its whole schedule in the contract and known from day one; Central Bank decisions do not change it, but the return you receive falls from one year to the next.
A hypothetical example per 100 EGP with a schedule of 22%, then 18%, then 14% and monthly payout: about 1.83 EGP a month in year 1, 1.50 in year 2 and about 1.17 in year 3.
That is why the big figure in an ad is usually year 1 only and is not 'the certificate's rate'. Ask for the full year-by-year schedule in the key-facts statement.