Not exactly, but there are many similarities between them. Spread betting can be used as part of a day trading strategy: you can make daily funded bets (DFB) which are spread bets that are designed to only remain open for a single day.
However, spread betting is tax-free, whereas standard day trading using CFDs is not. Spread betting is available in the UK and Ireland but not elsewhere, whereas day trading with CFDs is much more widely available.