Functional Specs are requirements of the business user.Technical Specs translate these requirements in a technical fashion.Let's say Functional Spec says,

1. the user should be able to enter the KEY date, Fiscal Year, Fiscal Version.
2. The Company variable should be defaulted to USA but then if the user wants to change it, they can check the drop down list and choose other countries.
3. The calculations or formulas for the report will be displayed in precision of one decimal POINT.
4. The report should return values for 12 months of data DEPENDING on the fiscal year that the user enters Or it should display in quarterly values. Functional specs are also called as Software requirements.

Now from this Technical Spec follows, to resolve each of the line items listed above.

1. To give the option of key date, Fiscal year and Fiscal Version – certain Info Objects should be available in the system. If available, then should we create any VARIABLES for them - so that they are used as user entry variable. To create any variables, what is the approach, where do you do it, what is the technical of the objects you'll use, what'll be the technical name of the objects you'll Crete as a result of this report.
2. Same explanation goes for the rest. How do you set up the variable,
3. What changes in PROPERTIES will you do to get the precision.
4. How will you get the 12 months of data. What will be the technical and display name of the report, who'll be authorized to run this report, etc are clearly specified in the technical specs.

Functional Specs are requirements of the business user.Technical Specs translate these requirements in a technical fashion.Let's say Functional Spec says,

Now from this Technical Spec follows, to resolve each of the line items listed above.