The ordinance is defining the term "tax" for the narrow purpose of the ordinance itself, which is more narrow the the general definition of the word tax in most respects (since it doesn't include non-ordinance imposes taxes), but broader than the word tax is other respects (since it includes interests and penalties and fees and the like). The terms "additional tax", and "excess profit tax" are defined terms in the ordinance and basically amount to penalties owed in addition to the ordinary "income tax" which is the primary kind of tax owed under the ordinance.
This definition means that as used in the ordinance, the term "tax" means all tax related amounts of money owed as a consequence of this particular ordinance, but no tax related amounts owed as a consequence of any other law.
There are other taxes in Bangladesh, for example, value added taxes and property taxes and fuel taxes and customs duties, that are excluded from the definition of tax as used in this ordinance.
This is done for drafting convenience, so that what is included and excluded in the concept defined as "tax" in the ordinance doesn't have to be reiterated every time the concept is used.
The diagram on the right is closer to the mark than the diagram on the left, since the definition includes "income tax" as well as other amounts within the definition of "tax". But it is still flawed because it doesn't include all of the other things that could plausibly be called taxes that are outside the circle and that are not included in this definition, such as taxes imposed by different laws. In equation form:
Tax = any income tax payable under this Ordinance + any additional tax under this Ordinance + any excess profit tax under this Ordinance + any penalty under this Ordinance + any interest under this Ordinance + any fee under this Ordinance + any other charges under this Ordinance.
Thus, "tax" and "income tax" are different things, where "tax" contains "income tax" along with others.
Another subtly of the definition is that only includes taxes and charges described in the ordinance that are "leviable or payable", which excludes tax obligations which are accrued but not yet payable.
For example, suppose that your 2020 income taxes were due on May 15, 2021, and you are in disputed with tax officials. As used in the ordinance, the term "taxes" includes your taxes from the 2020 tax year and all prior tax years for which the statute of limitations on collection of those taxes has not expired. But it does not include taxes that will be due in the future for the year 2021 on income that you have already earned in 2021, since those taxes aren't payable yet.