Don't understand query error explanation

[GraeagleBill]

SELECT TDate, Description, Credit, SUM(Credit) FROM tblRegister  
WHERE (TDate)>=#1/1/2021# And (TDate<=#12/31/2021#)
GROUP BY Description  
ORDER BY Description;

Each record in tblRegister contain Description, TDate and Credit fields. I'm just tying to get totals relating to each Description in the table.
Not being at all familiar with this type of query, I don't understand what the error message is trying to teach?

[isladogs]

All fields except SUM(Credit) need to be grouped

SELECT TDate, Description, Credit, SUM(Credit) 
FROM tblRegister  
WHERE (TDate)>=#1/1/2021# And (TDate<=#12/31/2021#)
GROUP BY TDate, Description, Credit 
ORDER BY Description;

If you had used the QBE, this would have been done automatically

[June7]

Every field in aggregate query SELECT clause not referenced in aggregate function calc must be included in GROUP BY clause. Remove TDate and Credit fields from SELECT clause.

SELECT Description, Sum(Credit) AS Total

[GraeagleBill]

Apparently, I've not described what I need clearly enough. For all records in tblRegister, total the amount of Credits for each Description group.
Example:
Description Total Credits
Portfolio Div $6,998,435.00
Portfolio Int $46,367.00
USA Stimulus $12,000.00

[GraeagleBill]

SELECT tblRegister.Description, Sum(tblRegister.Credit) AS SumOfCredit
FROM tblRegister
WHERE (((tblRegister.[TDate])>=#1/1/2021# And (tblRegister.[TDate])<=#12/31/2021#))
GROUP BY tblRegister.Description
HAVING (((Sum(tblRegister.Credit)) Is Not Null))
ORDER BY tblRegister.Description;

That did the trick June7, thanks.

[June7]

If you want to see raw data details as well as summary calcs, build a report and use its Sorting & Grouping features with aggregation in group section.

[GraeagleBill]

Yes, I remember doing that many years ago.
Thanks again,
Bill