1) Difference between billable and Non billable expenses

Billable expense

a) Billable expenses are expenses incurred by company, on behalf of the customer, in relation to the goods/service it sells/supplies to its customers.
b) Those expenses can be directly traced to company's core revenue-generating activities like sales commissions, customization charges for the product etc are billed as part of the invoice and are recovered from the customer.

Non-Billable expense

a) These are overhead expenses that are essential for the company's operations like rent, stationery, salary of those involved in work that are non-billable, finance charges and administrative costs etc.
b) Unlike billable expenses, these expenses cannot be attributed to a specific customer order or client project and hence these expenses cannot be recovered from customers.

2) Difference between Fiscal Year and Financial year

Fiscal year

a) Fiscal year is a term used by Governments (Government accounting) for accounting its tax revenues and expenditure outlays and for financial planning and budget purposes.
b) There can be only fiscal year applicable for country as a whole. There can be different fiscal year applicable for each country's Government.

Financial year

a) Financial Year is period for which business organisation/entities prepare and present their accounts.
b) Financial year might vary from entity to entity, even within a country.

3) Difference between Fixed Charge and Floating Charge

Fixed Charge

a) Is a charge created on specific identified tangible assets.
b) When a fixed charge is created, the borrower cannot sell or dispose off the asset, without specific consent of the lender.
c) In case of insolvency, fixed charge holders will rank above floating charge for the purpose of preference in settlement of dues.

Floating Charge

a) It is a general/Equitable charge created on the business assets as a whole, both present and future.
b) The borrower can deal (trade/dispose)with assets freely until crystalization occurs.
c) In case of insolvency, floating charge holders take a back seat and are settled only after the fixed charge holders, preferential creditors and cost of liquidation have been paid in full.