A debit spread is when a low premium option is sold and a high premium option is bought. This is the most common type of spread which you need to pay money to put on. Hence a "Debit" to your account. This debit to your account is where the term "Debit Spread" comes from. Anyone with enough money to pay the debit can put on a debit spread. There are no margin requirements and is therefore the most popular kind of spread.
Good examples would be a Calendar Put Spread and Options Margin.
Good examples would be a Calendar Put Spread and Options Margin.